Segalowitz, Norman S; Doucerain, Marina M; Meuter, Renata F I; Zhao, Yue; Hocking, Julia; Ryder, Andrew G
2016-01-01
This research explored the feasibility of using multidimensional scaling (MDS) analysis in novel combination with other techniques to study comprehension of epistemic adverbs expressing doubt and certainty (e.g., evidently, obviously, probably) as they relate to health communication in clinical settings. In Study 1, Australian English speakers performed a dissimilarity-rating task with sentence pairs containing the target stimuli, presented as "doctors' opinions." Ratings were analyzed using a combination of cultural consensus analysis (factor analysis across participants), weighted-data classical-MDS, and cluster analysis. Analyses revealed strong within-community consistency for a 3-dimensional semantic space solution that took into account individual differences, strong statistical acceptability of the MDS results in terms of stress and explained variance, and semantic configurations that were interpretable in terms of linguistic analyses of the target adverbs. The results confirmed the feasibility of using MDS in this context. Study 2 replicated the results with Canadian English speakers on the same task. Semantic analyses and stress decomposition analysis were performed on the Australian and Canadian data sets, revealing similarities and differences between the two groups. Overall, the results support using MDS to study comprehension of words critical for health communication, including in future studies, for example, second language speaking patients and/or practitioners. More broadly, the results indicate that the techniques described should be promising for comprehension studies in many communicative domains, in both clinical settings and beyond, and including those targeting other aspects of language and focusing on comparisons across different speech communities. PMID:27199798
Segalowitz, Norman S.; Doucerain, Marina M.; Meuter, Renata F. I.; Zhao, Yue; Hocking, Julia; Ryder, Andrew G.
2016-01-01
This research explored the feasibility of using multidimensional scaling (MDS) analysis in novel combination with other techniques to study comprehension of epistemic adverbs expressing doubt and certainty (e.g., evidently, obviously, probably) as they relate to health communication in clinical settings. In Study 1, Australian English speakers performed a dissimilarity-rating task with sentence pairs containing the target stimuli, presented as “doctors' opinions.” Ratings were analyzed using a combination of cultural consensus analysis (factor analysis across participants), weighted-data classical-MDS, and cluster analysis. Analyses revealed strong within-community consistency for a 3-dimensional semantic space solution that took into account individual differences, strong statistical acceptability of the MDS results in terms of stress and explained variance, and semantic configurations that were interpretable in terms of linguistic analyses of the target adverbs. The results confirmed the feasibility of using MDS in this context. Study 2 replicated the results with Canadian English speakers on the same task. Semantic analyses and stress decomposition analysis were performed on the Australian and Canadian data sets, revealing similarities and differences between the two groups. Overall, the results support using MDS to study comprehension of words critical for health communication, including in future studies, for example, second language speaking patients and/or practitioners. More broadly, the results indicate that the techniques described should be promising for comprehension studies in many communicative domains, in both clinical settings and beyond, and including those targeting other aspects of language and focusing on comparisons across different speech communities. PMID:27199798
ERIC Educational Resources Information Center
Paraschkewoff, Boris
1974-01-01
The contemporary German, predicate adjective and adjectival adverb are expressed by the same form. Although modern grammatical research gathers the various functions of the adjective under "indicator of kind," school practice still separates adjective and adverb. The historical development of qualitative adverbs is outlined. (Text is in German.)…
Sentence Adverbs in the Kingdom of Agree
ERIC Educational Resources Information Center
Shu, Chih-hsiang
2011-01-01
This dissertation offers a novel account of the syntax of sentence adverbs. The need for a new account is clear from the lack of descriptive coverage and theoretical coherence in current work on adverbial syntax. Descriptively, the majority of work has so far neglected the fact that sentence adverbs behave syntactically like typical focusing…
The Syntactic Positions of Adverbs and the Second Language Acquisition
ERIC Educational Resources Information Center
Zhang, Zi-hong
2010-01-01
Based on the theory of linguistic universal and Second Language Acquisition (SLA), the paper discusses the acquisition of syntactic positions of adverbs in English. According to the data collected, the paper concludes that what adult learners acquire about adverbs is the distinction of different adverbs and the different scopes they take.…
Robust, multidimensional mesh motion based on Monge-Kantorovich equidistribution
Delzanno, G L; Finn, J M
2009-01-01
Mesh-motion (r-refinement) grid adaptivity schemes are attractive due to their potential to minimize the numerical error for a prescribed number of degrees of freedom. However, a key roadblock to a widespread deployment of the technique has been the formulation of robust, reliable mesh motion governing principles, which (1) guarantee a solution in multiple dimensions (2D and 3D), (2) avoid grid tangling (or folding of the mesh, whereby edges of a grid cell cross somewhere in the domain), and (3) can be solved effectively and efficiently. In this study, we formulate such a mesh-motion governing principle, based on volume equidistribution via Monge-Kantorovich optimization (MK). In earlier publications [1, 2], the advantages of this approach in regards to these points have been demonstrated for the time-independent case. In this study, demonstrate that Monge-Kantorovich equidistribution can in fact be used effectively in a time stepping context, and delivers an elegant solution to the otherwise pervasive problem of grid tangling in mesh motion approaches, without resorting to ad-hoc time-dependent terms (as in moving-mesh PDEs, or MMPDEs [3, 4]). We explore two distinct r-refinement implementations of MK: direct, where the current mesh relates to an initial, unchanging mesh, and sequential, where the current mesh is related to the previous one in time. We demonstrate that the direct approach is superior in regards to mesh distortion and robustness. The properties of the approach are illustrated with a paradigmatic hyperbolic PDE, the advection of a passive scalar. Imposed velocity flow fields or varying vorticity levels and flow shears are considered.
"Mente" Adverbs, Compound Interpretation and the Projection Principle.
ERIC Educational Resources Information Center
Zagona, Karen
An analysis of the structure and interpretation of Spanish adverbs ending in "-mente" focuses on the grammatical status of the constituent elements of those words. It begins by looking at the grammatical properties of "-mente" adverbs (MAs), the word-level properties of MA constituents, and the compound types and their interpretation. It is argued…
Viola, Francesco; Coe, Ryan L.; Owen, Kevin; Guenther, Drake A.; Walker, William F.
2008-01-01
Image registration and motion estimation play central roles in many fields, including RADAR, SONAR, light microscopy, and medical imaging. Because of its central significance, estimator accuracy, precision, and computational cost are of critical importance. We have previously presented a highly accurate, spline-based time delay estimator that directly determines sub-sample time delay estimates from sampled data. The algorithm uses cubic splines to produce a continuous representation of a reference signal and then computes an analytical matching function between this reference and a delayed signal. The location of the minima of this function yields estimates of the time delay. In this paper we describe the MUlti-dimensional Spline-based Estimator (MUSE) that allows accurate and precise estimation of multidimensional displacements/strain components from multidimensional data sets. We describe the mathematical formulation for two- and three-dimensional motion/strain estimation and present simulation results to assess the intrinsic bias and standard deviation of this algorithm and compare it to currently available multi-dimensional estimators. In 1000 noise-free simulations of ultrasound data we found that 2D MUSE exhibits maximum bias of 2.6 × 10−4 samples in range and 2.2 × 10−3 samples in azimuth (corresponding to 4.8 and 297 nm, respectively). The maximum simulated standard deviation of estimates in both dimensions was comparable at roughly 2.8 × 10−3 samples (corresponding to 54 nm axially and 378 nm laterally). These results are between two and three orders of magnitude better than currently used 2D tracking methods. Simulation of performance in 3D yielded similar results to those observed in 2D. We also present experimental results obtained using 2D MUSE on data acquired by an Ultrasonix Sonix RP imaging system with an L14-5/38 linear array transducer operating at 6.6 MHz. While our validation of the algorithm was performed using ultrasound data, MUSE
Robustness of one-dimensional viscous fluid motion under multidimensional perturbations
NASA Astrophysics Data System (ADS)
Feireisl, Eduard; Sun, Yongzhong
2015-12-01
We adapt the relative energy functional associated to the compressible Navier-Stokes system to show stability of solutions emanating from 1-D initial data with respect to multidimensional N = 2, 3 perturbations. Besides the application of the relative energy inequality as a suitable "distance" between two solutions, refined regularity estimates in Lp based Sobolev spaces are used.
Adverb Code-Switching among Miami's Haitian Creole-English Second Generation
ERIC Educational Resources Information Center
Hebblethwaite, Benjamin
2010-01-01
The findings for adverbs and adverbial phrases in a naturalistic corpus of Miami Haitian Creole-English code-switching show that one language, Haitian Creole, asymmetrically supplies the grammatical frame while the other language, English, asymmetrically supplies mixed lexical categories like adverbs. Traces of code-switching with an English frame…
Figure and Ground in Temporal Sentences: The Role of the Adverbs "When" and "While"
ERIC Educational Resources Information Center
De Vega, Manuel; Rinck, Mike; Diaz, Jose; Leon, Inmaculada
2007-01-01
Multiclause sentences with the temporal adverbs "while" or "when" referring to simultaneous events (e.g., "While [when] John was writing a letter, Mary comes into the room") were compared in German and Spanish. Following Talmy (2001), we assumed that the event in the main clause is the figure (F; the event to be located in time), and the event in…
Zanni, Martin Thomas; Damrauer, Niels H.
2010-07-20
A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.
ERIC Educational Resources Information Center
Zierer, Ernesto
1971-01-01
This paper considers Spanish adjectives and the possibility of converting some adjectives into adverbs, keeping the same general significance of a sentence. The conversion of an adjective into an adverb under these circumstances can be accomplished through a transformation which can be applied to a particular logical-semantic structure. The author…
ERIC Educational Resources Information Center
Criado de Val, Manuel
1973-01-01
Compares use of pronouns and adverbs in Spanish, French, Italian, Portuguese, English, German, Rumanian, and Slavic languages. Excerpted from the book Fisonomia del y de las lenguas modernas'' ( Features of Modern Languages''). (DS)
ERIC Educational Resources Information Center
Gerhart, James B.; Nussbaum, Rudi H.
This monograph was written for the Conference on the New Instructional Materials in Physics held at the University of Washington in summer, 1965. It is intended for use in an introductory course in college physics. It consists of an extensive qualitative discussion of motion followed by a detailed development of the quantitative methods needed to…
ERIC Educational Resources Information Center
Brand, Judith, Ed.
2002-01-01
This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…
Papesh, Megan H.; Goldinger, Stephen D.
2012-01-01
The concept of similarity, or a sense of "sameness" among things, is pivotal to theories in the cognitive sciences and beyond. Similarity, however, is a difficult thing to measure. Multidimensional scaling (MDS) is a tool by which researchers can obtain quantitative estimates of similarity among groups of items. More formally, MDS refers to a set of statistical techniques that are used to reduce the complexity of a data set, permitting visual appreciation of the underlying relational structures contained therein. The current paper provides an overview of MDS. We discuss key aspects of performing this technique, such as methods that can be used to collect similarity estimates, analytic techniques for treating proximity data, and various concerns regarding interpretation of the MDS output. MDS analyses of two novel data sets are also included, highlighting in step-by-step fashion how MDS is performed, and key issues that may arise during analysis. PMID:23359318
Preface: Special Topic on Multidimensional Spectroscopy
Mukamel, Shaul; Bakker, Huib J.
2015-06-07
Multidimensional signals are generated by subjecting molecules to sequences of short optical pulses and recording correlation plots related to the various controlled delay periods. These techniques which span all the way from the THz to the x-ray regimes provide qualitatively new structural and dynamical molecular information not available from conventional one-dimensional techniques. This issue surveys the recent experimental and theoretical progresses in this rapidly developing 20 year old field which illustrates the novel insights provided by multidimensional techniques into electronic and nuclear motions. It should serve as a valuable source for experts in the field and help introduce newcomers to this exciting and challenging branch of nonlinear spectroscopy.
Preface: Special Topic on Multidimensional Spectroscopy
NASA Astrophysics Data System (ADS)
Mukamel, Shaul; Bakker, Huib J.
2015-06-01
Multidimensional signals are generated by subjecting molecules to sequences of short optical pulses and recording correlation plots related to the various controlled delay periods. These techniques which span all the way from the THz to the x-ray regimes provide qualitatively new structural and dynamical molecular information not available from conventional one-dimensional techniques. This issue surveys the recent experimental and theoretical progresses in this rapidly developing 20 year old field which illustrates the novel insights provided by multidimensional techniques into electronic and nuclear motions. It should serve as a valuable source for experts in the field and help introduce newcomers to this exciting and challenging branch of nonlinear spectroscopy.
Multidimensional Risk Analysis: MRISK
NASA Technical Reports Server (NTRS)
McCollum, Raymond; Brown, Douglas; O'Shea, Sarah Beth; Reith, William; Rabulan, Jennifer; Melrose, Graeme
2015-01-01
Multidimensional Risk (MRISK) calculates the combined multidimensional score using Mahalanobis distance. MRISK accounts for covariance between consequence dimensions, which de-conflicts the interdependencies of consequence dimensions, providing a clearer depiction of risks. Additionally, in the event the dimensions are not correlated, Mahalanobis distance reduces to Euclidean distance normalized by the variance and, therefore, represents the most flexible and optimal method to combine dimensions. MRISK is currently being used in NASA's Environmentally Responsible Aviation (ERA) project o assess risk and prioritize scarce resources.
Multidimensional spectral load balancing
Hendrickson, B.; Leland, R.
1993-01-01
We describe an algorithm for the static load balancing of scientific computations that generalizes and improves upon spectral bisection. Through a novel use of multiple eigenvectors, our new spectral algorithm can divide a computation into 4 or 8 pieces at once. These multidimensional spectral partitioning algorithms generate balanced partitions that have lower communication overhead and are less expensive to compute than those produced by spectral bisection. In addition, they automatically work to minimize message contention on a hypercube or mesh architecture. These spectral partitions are further improved by a multidimensional generalization of the Kernighan-Lin graph partitioning algorithm. Results on several computational grids are given and compared with other popular methods.
Preface: Special Topic on Multidimensional Spectroscopy.
Mukamel, Shaul; Bakker, Huib J
2015-06-01
Multidimensional signals are generated by subjecting molecules to sequences of short optical pulses and recording correlation plots related to the various controlled delay periods. These techniques which span all the way from the THz to the x-ray regimes provide qualitatively new structural and dynamical molecular information not available from conventional one-dimensional techniques. This issue surveys the recent experimental and theoretical progresses in this rapidly developing 20 year old field which illustrates the novel insights provided by multidimensional techniques into electronic and nuclear motions. It should serve as a valuable source for experts in the field and help introduce newcomers to this exciting and challenging branch of nonlinear spectroscopy. PMID:26049418
Probabilistic, Multidimensional Unfolding Analysis
ERIC Educational Resources Information Center
Zinnes, Joseph L.; Griggs, Richard A.
1974-01-01
Probabilistic assumptions are added to single and multidimensional versions of the Coombs unfolding model for preferential choice (Coombs, 1950) and practical ways of obtaining maximum likelihood estimates of the scale parameters and goodness-of-fit tests of the model are presented. A Monte Carlo experiment is discussed. (Author/RC)
Visualization of multidimensional database
NASA Astrophysics Data System (ADS)
Lee, Chung
2008-01-01
The concept of multidimensional databases has been extensively researched and wildly used in actual database application. It plays an important role in contemporary information technology, but due to the complexity of its inner structure, the database design is a complicated process and users are having a hard time fully understanding and using the database. An effective visualization tool for higher dimensional information system helps database designers and users alike. Most visualization techniques focus on displaying dimensional data using spreadsheets and charts. This may be sufficient for the databases having three or fewer dimensions but for higher dimensions, various combinations of projection operations are needed and a full grasp of total database architecture is very difficult. This study reviews existing visualization techniques for multidimensional database and then proposes an alternate approach to visualize a database of any dimension by adopting the tool proposed by Kiviat for software engineering processes. In this diagramming method, each dimension is represented by one branch of concentric spikes. This paper documents a C++ based visualization tool with extensive use of OpenGL graphics library and GUI functions. Detailed examples of actual databases demonstrate the feasibility and effectiveness in visualizing multidimensional databases.
Multidimensional reactor kinetics modeling
Diamond, D.J.
1996-11-01
There is general agreement that for many light water reactor transient calculations, it is-necessary to use a multidimensional neutron kinetics model coupled to a thermal-hydraulics model for satisfactory results. These calculations are needed for a variety of applications for licensing safety analysis, probabilistic risk assessment (PRA), operational support, and training. The latter three applications have always required best-estimate models, but in the past applications for licensing could be satisfied with relatively simple models. By using more sophisticated best-estimate models, the consequences of these calculations are better understood, and the potential for gaining relief from restrictive operating limits increases. Hence, for all of the aforementioned applications, it is important to have the ability to do best-estimate calculations with multidimensional neutron kinetics models. coupled to sophisticated thermal-hydraulic models. Specifically, this paper reviews the status of multidimensional neutron kinetics modeling which would be used in conjunction with thermal-hydraulic models to do core dynamics calculations, either coupled to a complete NSSS representation or in isolation. In addition, the paper makes recommendations as to what should be the state-of-the-art for the next ten years. The review is an update to a previous review of the status as of ten years ago. The general requirements for a core dynamics code and the modeling available for such a code, discussed in that review, are still applicable. The emphasis in the current review is on the neutron kinetics assuming that the necessary thermal-hydraulic capability exists. In addition to discussing the basic neutron kinetics, discussion is given of related modeling (other than thermal- hydraulics). The capabilities and limitations of current computer codes are presented to understand the state-of-the-art and to help clarify the future direction of model development in this area.
Multidimensional Potential Burgers Turbulence
NASA Astrophysics Data System (ADS)
Boritchev, Alexandre
2016-03-01
We consider the multidimensional generalised stochastic Burgers equation in the space-periodic setting: partial {u}/partial t+(nabla f({u}) \\cdot nabla) {u}-ν Δ {u}= nabla η, quad t ≥ 0, {x} in{T}^d=({R}/ {Z})^d, under the assumption that u is a gradient. Here f is strongly convex and satisfies a growth condition, ν is small and positive, while η is a random forcing term, smooth in space and white in time. For solutions u of this equation, we study Sobolev norms of u averaged in time and in ensemble: each of these norms behaves as a given negative power of ν. These results yield sharp upper and lower bounds for natural analogues of quantities characterising the hydrodynamical turbulence, namely the averages of the increments and of the energy spectrum. These quantities behave as a power of the norm of the relevant parameter, which is respectively the separation ℓ in the physical space and the wavenumber k in the Fourier space. Our bounds do not depend on the initial condition and hold uniformly in {ν}. We generalise the results obtained for the one-dimensional case in [10], confirming the physical predictions in [4, 30]. Note that the form of the estimates does not depend on the dimension: the powers of {ν, |{{k}}|, ℓ} are the same in the one- and the multi-dimensional setting.
Theta vocabulary II. Multidimensional case
NASA Astrophysics Data System (ADS)
Kharchev, S.; Zabrodin, A.
2016-06-01
It is shown that the Jacobi and Riemann identities of degree four for the multidimensional theta functions as well as the Weierstrass identities emerge as algebraic consequences of the fundamental multidimensional binary identities connecting the theta functions with Riemann matrices τ and 2 τ.
Multidimensional Perfectionism and the Self
ERIC Educational Resources Information Center
Ward, Andrew M.; Ashby, Jeffrey S.
2008-01-01
This study examined multidimensional perfectionism and self-development. Two hundred seventy-one undergraduates completed a measure of multidimensional perfectionism and two Kohutian measures designed to measure aspects of self-development including social connectedness, social assurance, goal instability (idealization), and grandiosity. The…
Modeling, calculating, and analyzing multidimensional vibrational spectroscopies.
Tanimura, Yoshitaka; Ishizaki, Akihito
2009-09-15
Spectral line shapes in a condensed phase contain information from various dynamic processes that modulate the transition energy, such as microscopic dynamics, inter- and intramolecular couplings, and solvent dynamics. Because nonlinear response functions are sensitive to the complex dynamics of chemical processes, multidimensional vibrational spectroscopies can separate these processes. In multidimensional vibrational spectroscopy, the nonlinear response functions of a molecular dipole or polarizability are measured using ultrashort pulses to monitor inter- and intramolecular vibrational motions. Because a complex profile of such signals depends on the many dynamic and structural aspects of a molecular system, researchers would like to have a theoretical understanding of these phenomena. In this Account, we explore and describe the roles of different physical phenomena that arise from the peculiarities of the system-bath coupling in multidimensional spectra. We also present simple analytical expressions for a weakly coupled multimode Brownian system, which we use to analyze the results obtained by the experiments and simulations. To calculate the nonlinear optical response, researchers commonly use a particular form of a system Hamiltonian fit to the experimental results. The optical responses of molecular vibrational motions have been studied in either an oscillator model or a vibration energy state model. In principle, both models should give the same results as long as the energy states are chosen to be the eigenstates of the oscillator model. The energy state model can provide a simple description of nonlinear optical processes because the diagrammatic Liouville space theory that developed in the electronically resonant spectroscopies can easily handle three or four energy states involved in high-frequency vibrations. However, the energy state model breaks down if we include the thermal excitation and relaxation processes in the dynamics to put the system in a
Multidimensional persistence in biomolecular data
Xia, Kelin; Wei, Guo-Wei
2015-01-01
Persistent homology has emerged as a popular technique for the topological simplification of big data, including biomolecular data. Multidimensional persistence bears considerable promise to bridge the gap between geometry and topology. However, its practical and robust construction has been a challenge. We introduce two families of multidimensional persistence, namely pseudo-multidimensional persistence and multiscale multidimensional persistence. The former is generated via the repeated applications of persistent homology filtration to high dimensional data, such as results from molecular dynamics or partial differential equations. The latter is constructed via isotropic and anisotropic scales that create new simiplicial complexes and associated topological spaces. The utility, robustness and efficiency of the proposed topological methods are demonstrated via protein folding, protein flexibility analysis, the topological denoising of cryo-electron microscopy data, and the scale dependence of nano particles. Topological transition between partial folded and unfolded proteins has been observed in multidimensional persistence. The separation between noise topological signatures and molecular topological fingerprints is achieved by the Laplace-Beltrami flow. The multiscale multidimensional persistent homology reveals relative local features in Betti-0 invariants and the relatively global characteristics of Betti-1 and Betti-2 invariants. PMID:26032339
Multidimensional Electronic Spectroscopy of Photochemical Reactions.
Nuernberger, Patrick; Ruetzel, Stefan; Brixner, Tobias
2015-09-21
Coherent multidimensional electronic spectroscopy can be employed to unravel various channels in molecular chemical reactions. This approach is thus not limited to analysis of energy transfer or charge transfer (i.e. processes from photophysics), but can also be employed in situations where the investigated system undergoes permanent structural changes (i.e. in photochemistry). Photochemical model reactions are discussed by using the example of merocyanine/spiropyran-based molecular switches, which show a rich variety of reaction channels, in particular ring opening and ring closing, cis-trans isomerization, coherent vibrational wave-packet motion, radical ion formation, and population relaxation. Using pump-probe, pump-repump-probe, coherent two-dimensional and three-dimensional, triggered-exchange 2D, and quantum-control spectroscopy, we gain intuitive pictures on which product emerges from which reactant and which reactive molecular modes are associated. PMID:26382095
Multidimensional persistence in biomolecular data.
Xia, Kelin; Wei, Guo-Wei
2015-07-30
Persistent homology has emerged as a popular technique for the topological simplification of big data, including biomolecular data. Multidimensional persistence bears considerable promise to bridge the gap between geometry and topology. However, its practical and robust construction has been a challenge. We introduce two families of multidimensional persistence, namely pseudomultidimensional persistence and multiscale multidimensional persistence. The former is generated via the repeated applications of persistent homology filtration to high-dimensional data, such as results from molecular dynamics or partial differential equations. The latter is constructed via isotropic and anisotropic scales that create new simiplicial complexes and associated topological spaces. The utility, robustness, and efficiency of the proposed topological methods are demonstrated via protein folding, protein flexibility analysis, the topological denoising of cryoelectron microscopy data, and the scale dependence of nanoparticles. Topological transition between partial folded and unfolded proteins has been observed in multidimensional persistence. The separation between noise topological signatures and molecular topological fingerprints is achieved by the Laplace-Beltrami flow. The multiscale multidimensional persistent homology reveals relative local features in Betti-0 invariants and the relatively global characteristics of Betti-1 and Betti-2 invariants. PMID:26032339
On the Need for Multidimensional Stirling Simulations
NASA Technical Reports Server (NTRS)
Dyson, Rodger W.; Wilson, Scott D.; Tew, Roy C.; Demko, Rikako
2005-01-01
Given the cost and complication of simulating Stirling convertors, do we really need multidimensional modeling when one-dimensional capabilities exist? This paper provides a comprehensive description of when and why multidimensional simulation is needed.
Ultrafast Multidimensional Laplace NMR Using a Single-Sided Magnet.
King, Jared N; Lee, Vanessa J; Ahola, Susanna; Telkki, Ville-Veikko; Meldrum, Tyler
2016-04-11
Laplace NMR (LNMR) consists of relaxation and diffusion measurements providing detailed information about molecular motion and interaction. Here we demonstrate that ultrafast single- and multidimensional LNMR experiments, based on spatial encoding, are viable with low-field, single-sided magnets with an inhomogeneous magnetic field. This approach shortens the experiment time by one to two orders of magnitude relative to traditional experiments, and increases the sensitivity per unit time by a factor of three. The reduction of time required to collect multidimensional data opens significant prospects for mobile chemical analysis using NMR. Particularly tantalizing is future use of hyperpolarization to increase sensitivity by orders of magnitude, allowed by single-scan approach. PMID:26960011
Recycling Behavior: A Multidimensional Approach
ERIC Educational Resources Information Center
Meneses, Gonzalo Diaz; Palacio, Asuncion Beerli
2005-01-01
This work centers on the study of consumer recycling roles to examine the sociodemographic and psychographic profile of the distribution of recycling tasks and roles within the household. With this aim in mind, an empirical work was carried out, the results of which suggest that recycling behavior is multidimensional and comprises the undertaking…
Multidimensional Scaling of Video Surrogates.
ERIC Educational Resources Information Center
Goodrum, Abby A.
2001-01-01
Four types of video surrogates were compared under two tasks. Multidimensional scaling was used to map dimensional dispersions of users' judgments of similarity between videos and surrogates. Congruence between these maps was used to evaluate representativeness of each surrogate type. Congruence was greater for image-based than for text-based…
A Multidimensional Software Engineering Course
ERIC Educational Resources Information Center
Barzilay, O.; Hazzan, O.; Yehudai, A.
2009-01-01
Software engineering (SE) is a multidimensional field that involves activities in various areas and disciplines, such as computer science, project management, and system engineering. Though modern SE curricula include designated courses that address these various subjects, an advanced summary course that synthesizes them is still missing. Such a…
Multidimensional optics and dynamics of liquid crystals
NASA Astrophysics Data System (ADS)
Tang, Shouping
2007-12-01
In this dissertation, we present an alternative description of multidimensional optics in liquid crystals and uniaxial media, and a systematical investigation on the dynamic properties of twist nematic devices and ECB devices including flow. We also present our investigation on the backflow and dynamic properties of nematic liquid crystals in modulated electric fields. Based on the understanding to backflow and dynamics of liquid crystals, the dynamics of colloidal particles dispersed in nematic liquid crystals and the flow-induced dynamic optical crosstalk between pixels in nematic liquid crystal devices are also studied. The alternative description of multidimensional optics combines the geometrical optics approximation (GOA) with the beam propagation method (BPM). The general treatment of this approach is developed both theoretically and numerically. The investigation on the dynamic properties of twist nematic devices and ECB devices with consideration of backflow is done experimentally, theoretically and numerically. The calculation results are compared with the experimental results, and the optical responses due to backflow are discussed in detail. The investigation on the backflow and dynamic properties of a nematic liquid crystal in modulated electric fields includes director, flow and the shift of liquid crystal fluid. Especially, an important phenomenon, reverseswitching, is shown in this investigation. The dynamics of colloidal particles dispersed in a nematic cela is studied experimentally and by computer simulation. The polarity of director distortions determines the direction of lift force, and the backflow is responsible for the horizontal translational motion. The optical crosstalk between pixels demonstrates the significance of switching-induce flow in pixilated devices. The electrical switching of a pixel in a twisted nematic device can induce an optical response in neighboring pixels. These phenomena are studied in detail, both experimentally and
Mixing Study in a Multi-dimensional Motion Mixer
NASA Astrophysics Data System (ADS)
Shah, R.; Manickam, S. S.; Tomei, J.; Bergman, T. L.; Chaudhuri, B.
2009-06-01
Mixing is an important but poorly understood aspect in petrochemical, food, ceramics, fertilizer and pharmaceutical processing and manufacturing. Deliberate mixing of granular solids is an essential operation in the production of industrial powder products usually constituted from different ingredients. The knowledge of particle flow and mixing in a blender is critical to optimize the design and operation. Since performance of the product depends on blend homogeneity, the consequence of variability can be detrimental. A common approach to powder mixing is to use a tumbling blender, which is essentially a hollow vessel horizontally attached to a rotating shaft. This single axis rotary blender is one of the most common batch mixers among in industry, and also finds use in myriad of application as dryers, kilns, coaters, mills and granulators. In most of the rotary mixers the radial convection is faster than axial dispersion transport. This slow dispersive process hinders mixing performance in many blending, drying and coating applications. A double cone mixer is designed and fabricated which rotates around two axes, causing axial mixing competitive to its radial counterpart. Discrete Element Method (DEM) based numerical model is developed to simulate the granular flow within the mixer. Digitally recorded mixing states from experiments are used to fine tune the numerical model. Discrete pocket samplers are also used in the experiments to quantify the characteristics of mixing. A parametric study of the effect of vessel speeds, relative rotational speed (between two axes of rotation), on the granular mixing is investigated by experiments and numerical simulation. Incorporation of dual axis rotation enhances axial mixing by 60 to 85% in comparison to single axis rotation.
Multidimensional signatures in antimicrobial peptides
Yount, Nannette Y.; Yeaman, Michael R.
2004-01-01
Conventional analyses distinguish between antimicrobial peptides by differences in amino acid sequence. Yet structural paradigms common to broader classes of these molecules have not been established. The current analyses examined the potential conservation of structural themes in antimicrobial peptides from evolutionarily diverse organisms. Using proteomics, an antimicrobial peptide signature was discovered to integrate stereospecific sequence patterns and a hallmark three-dimensional motif. This striking multidimensional signature is conserved among disulfide-containing antimicrobial peptides spanning biological kingdoms, and it transcends motifs previously limited to defined peptide subclasses. Experimental data validating this model enabled the identification of previously unrecognized antimicrobial activity in peptides of known identity. The multidimensional signature model provides a unifying structural theme in broad classes of antimicrobial peptides, will facilitate discovery of antimicrobial peptides as yet unknown, and offers insights into the evolution of molecular determinants in these and related host defense effector molecules. PMID:15118082
Deterministic multidimensional nonuniform gap sampling
NASA Astrophysics Data System (ADS)
Worley, Bradley; Powers, Robert
2015-12-01
Born from empirical observations in nonuniformly sampled multidimensional NMR data relating to gaps between sampled points, the Poisson-gap sampling method has enjoyed widespread use in biomolecular NMR. While the majority of nonuniform sampling schemes are fully randomly drawn from probability densities that vary over a Nyquist grid, the Poisson-gap scheme employs constrained random deviates to minimize the gaps between sampled grid points. We describe a deterministic gap sampling method, based on the average behavior of Poisson-gap sampling, which performs comparably to its random counterpart with the additional benefit of completely deterministic behavior. We also introduce a general algorithm for multidimensional nonuniform sampling based on a gap equation, and apply it to yield a deterministic sampling scheme that combines burst-mode sampling features with those of Poisson-gap schemes. Finally, we derive a relationship between stochastic gap equations and the expectation value of their sampling probability densities.
Cuba: Multidimensional numerical integration library
NASA Astrophysics Data System (ADS)
Hahn, Thomas
2016-08-01
The Cuba library offers four independent routines for multidimensional numerical integration: Vegas, Suave, Divonne, and Cuhre. The four algorithms work by very different methods, and can integrate vector integrands and have very similar Fortran, C/C++, and Mathematica interfaces. Their invocation is very similar, making it easy to cross-check by substituting one method by another. For further safeguarding, the output is supplemented by a chi-square probability which quantifies the reliability of the error estimate.
Multidimensional scaling of pictorial informativeness.
Antes, J R; Stone, L A
1975-06-01
The dimensions used in the judgment of the informativeness of picture sections were investigated by means of a recently proposed methodology, multidimensional similarity analysis. 10 judges (college students) rated the informational similarity of 32 areas within a single picture. The five extracted dimensions accounted for 86% of the judgmental variance and were all readily interpretable. These dimensions were discussed with respect to an earlier study in which eye movements of subjects viewing this picture were recorded. PMID:1178379
Multidimensional bioseparation with modular microfluidics
Chirica, Gabriela S.; Renzi, Ronald F.
2013-08-27
A multidimensional chemical separation and analysis system is described including a prototyping platform and modular microfluidic components capable of rapid and convenient assembly, alteration and disassembly of numerous candidate separation systems. Partial or total computer control of the separation system is possible. Single or multiple alternative processing trains can be tested, optimized and/or run in parallel. Examples related to the separation and analysis of human bodily fluids are given.
2015-01-01
Conformational motions of proteins are highly dynamic and intrinsically complex. To capture the temporal and spatial complexity of conformational motions and further to understand their roles in protein functions, an attempt is made to probe multidimensional conformational dynamics of proteins besides the typical one-dimensional FRET coordinate or the projected conformational motions on the one-dimensional FRET coordinate. T4 lysozyme hinge-bending motions between two domains along α-helix have been probed by single-molecule FRET. Nevertheless, the domain motions of T4 lysozyme are rather complex involving multiple coupled nuclear coordinates and most likely contain motions besides hinge-bending. It is highly likely that the multiple dimensional protein conformational motions beyond the typical enzymatic hinged-bending motions have profound impact on overall enzymatic functions. In this report, we have developed a single-molecule multiparameter photon stamping spectroscopy integrating fluorescence anisotropy, FRET, and fluorescence lifetime. This spectroscopic approach enables simultaneous observations of both FRET-related site-to-site conformational dynamics and molecular rotational (or orientational) motions of individual Cy3-Cy5 labeled T4 lysozyme molecules. We have further observed wide-distributed rotational flexibility along orientation coordinates by recording fluorescence anisotropy and simultaneously identified multiple intermediate conformational states along FRET coordinate by monitoring time-dependent donor lifetime, presenting a whole picture of multidimensional conformational dynamics in the process of T4 lysozyme open-close hinge-bending enzymatic turnover motions under enzymatic reaction conditions. By analyzing the autocorrelation functions of both lifetime and anisotropy trajectories, we have also observed the dynamic and static inhomogeneity of T4 lysozyme multidimensional conformational fluctuation dynamics, providing a fundamental
Quasilinearization method applied to multidimensional quantum tunneling
NASA Astrophysics Data System (ADS)
Razavy, M.; Cote, Vincent J.
1994-04-01
We apply the quasilinearization method of Bellman and Kalaba [Quasilinearization and Nonlinear Boundary-Value Problems (Elsevier, New York, 1965)] to find approximate solutions for the multidimensional quantum tunneling for separable as well as nonseparable wave equations. By introducing the idea of the complex ``semiclassical trajectory'' which is valid for the motion over and under the barrier, and which, in the proper limit, reduces to the real classical trajectory in the allowed region, we obtain an eigenvalue equation for the characteristic wave numbers. This eigenvalue equation is similar to the corresponding equation obtained from the WKB approximation and yields complex eigenvalues with negative imaginary parts. When the barrier changes very rapidly as a function of the radial distance, we can replace the concept of the semiclassical trajectory, which may not be applicable in this case, by the concept of a complex ``quantum trajectory.'' The trajectory defined either way depends on a constant of integration, and by minimizing the action with respect to this constant we can obtain the minimum escape path. The case of two-dimensional tunneling is discussed as an example of this method.
Measures for a multidimensional multiverse
NASA Astrophysics Data System (ADS)
Chung, Hyeyoun
2015-04-01
We explore the phenomenological implications of generalizing the causal patch and fat geodesic measures to a multidimensional multiverse, where the vacua can have differing numbers of large dimensions. We consider a simple model in which the vacua are nucleated from a D -dimensional parent spacetime through dynamical compactification of the extra dimensions, and compute the geometric contribution to the probability distribution of observations within the multiverse for each measure. We then study how the shape of this probability distribution depends on the time scales for the existence of observers, for vacuum domination, and for curvature domination (tobs,tΛ , and tc, respectively.) In this work we restrict ourselves to bubbles with positive cosmological constant, Λ . We find that in the case of the causal patch cutoff, when the bubble universes have p +1 large spatial dimensions with p ≥2 , the shape of the probability distribution is such that we obtain the coincidence of time scales tobs˜tΛ˜tc . Moreover, the size of the cosmological constant is related to the size of the landscape. However, the exact shape of the probability distribution is different in the case p =2 , compared to p ≥3 . In the case of the fat geodesic measure, the result is even more robust: the shape of the probability distribution is the same for all p ≥2 , and we once again obtain the coincidence tobs˜tΛ˜tc . These results require only very mild conditions on the prior probability of the distribution of vacua in the landscape. Our work shows that the observed double coincidence of time scales is a robust prediction even when the multiverse is generalized to be multidimensional; that this coincidence is not a consequence of our particular Universe being (3 +1 )-dimensional; and that this observable cannot be used to preferentially select one measure over another in a multidimensional multiverse.
Preconditioning for multidimensional TOMBO imaging.
Horisaki, Ryoichi; Tanida, Jun
2011-06-01
In this Letter, we propose a preconditioning method to improve the convergence speed of iterative reconstruction algorithms in a compact, multidimensional, compound-eye imaging system called the thin observation module by bound optics. The condition number of the system matrix is improved by using a preconditioner matrix. To calculate the preconditioner matrix, the system model is expressed in the frequency domain. The proposed method is simulated by using a compressive sensing algorithm called the two-step iterative shrinkage/thresholding algorithm. The results showed improved reconstruction fidelity with a certain number of iterations for high signal-to-noise ratio measurements. PMID:21633452
On Compensation in Multidimensional Response Modeling
ERIC Educational Resources Information Center
van der Linden, Wim J.
2012-01-01
The issue of compensation in multidimensional response modeling is addressed. We show that multidimensional response models are compensatory in their ability parameters if and only if they are monotone. In addition, a minimal set of assumptions is presented under which the MLEs of the ability parameters are also compensatory. In a recent series of…
Multidimensional Scaling of Classroom Interaction Data.
ERIC Educational Resources Information Center
Rumery, Robert E.; Hartnett, Barbara M.
The use of Kruskal's nonmetric multidimensional scaling model for analysis of classroom interaction data is discussed. Four distance models are proposed which lead to multidimensional representation of single sequences, sets of sequences, and behavior categories using symmetric and conditional proximity options of the model. Results of application…
A multidimensional version of the ziggurat algorithm
NASA Astrophysics Data System (ADS)
Shmerling, Efraim
2016-06-01
It is shown that the widely applied ziggurat algorithm for generating random values from monotone decreasing distributions and symmetric unimodal distributions can be extended to unimodal multidimensional distributions. A multidimensional version of the ziggurat that was implemented in very fast random number generators is presented.
Gordon, R.G. )
1991-01-01
The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.
The Multidimensional Audioconferencing Classification System (MACS).
ERIC Educational Resources Information Center
Cookson, Peter S.; Chang, Yu-bi
1995-01-01
Describes the development of the Multidimensional Audioconferencing Classification System (MACS), an instrument for the tabulation, analysis, and interpretation of audioconferencing instructional interactions. MACS draws on three theoretical and empirical streams: (1) systematic small group interaction analysis; (2) systematic classroom…
Tourette Syndrome: A Multidimensional Approach to Treatment.
ERIC Educational Resources Information Center
Anderson, Donna J.
1987-01-01
Describes Tourette syndrome, a chronic, neurological disorder characterized by involuntary muscular movements, uncontrollable sounds, and inappropriate words. Notes that Tourette syndrome is frequently misunderstood and mistreated, presents symptoms, and suggests a multidimensional approach to treatment. (Author/NB)
The Multidimensional Assessment of Interoceptive Awareness (MAIA)
Mehling, Wolf E.; Price, Cynthia; Daubenmier, Jennifer J.; Acree, Mike; Bartmess, Elizabeth; Stewart, Anita
2012-01-01
This paper describes the development of a multidimensional self-report measure of interoceptive body awareness. The systematic mixed-methods process involved reviewing the current literature, specifying a multidimensional conceptual framework, evaluating prior instruments, developing items, and analyzing focus group responses to scale items by instructors and patients of body awareness-enhancing therapies. Following refinement by cognitive testing, items were field-tested in students and instructors of mind-body approaches. Final item selection was achieved by submitting the field test data to an iterative process using multiple validation methods, including exploratory cluster and confirmatory factor analyses, comparison between known groups, and correlations with established measures of related constructs. The resulting 32-item multidimensional instrument assesses eight concepts. The psychometric properties of these final scales suggest that the Multidimensional Assessment of Interoceptive Awareness (MAIA) may serve as a starting point for research and further collaborative refinement. PMID:23133619
Mormons and Social Distance: A Multidimensional Analysis
ERIC Educational Resources Information Center
Bunker, Gary L.; And Others
1977-01-01
Issues such as Mormon variation from general cultural ethnic attitudes and generalization from ecclesiastical norms to secular tolerance/intolerance are examined in light of multi-dimensional research. (Author/AM)
Multidimensional Data Modeling for Business Process Analysis
NASA Astrophysics Data System (ADS)
Mansmann, Svetlana; Neumuth, Thomas; Scholl, Marc H.
The emerging area of business process intelligence attempts to enhance the analytical capabilities of business process management systems by employing data warehousing and mining technologies. This paper presents an approach to re-engineering the business process modeling in conformity with the multidimensional data model. Since the business process and the multidimensional model are driven by rather different objectives and assumptions, there is no straightforward solution to converging these models.
VH-1: Multidimensional ideal compressible hydrodynamics code
NASA Astrophysics Data System (ADS)
Hawley, John; Blondin, John; Lindahl, Greg; Lufkin, Eric
2012-04-01
VH-1 is a multidimensional ideal compressible hydrodynamics code written in FORTRAN for use on any computing platform, from desktop workstations to supercomputers. It uses a Lagrangian remap version of the Piecewise Parabolic Method developed by Paul Woodward and Phil Colella in their 1984 paper. VH-1 comes in a variety of versions, from a simple one-dimensional serial variant to a multi-dimensional version scalable to thousands of processors.
Multidimensional Poverty and Child Survival in India
Mohanty, Sanjay K.
2011-01-01
Background Though the concept of multidimensional poverty has been acknowledged cutting across the disciplines (among economists, public health professionals, development thinkers, social scientists, policy makers and international organizations) and included in the development agenda, its measurement and application are still limited. Objectives and Methodology Using unit data from the National Family and Health Survey 3, India, this paper measures poverty in multidimensional space and examine the linkages of multidimensional poverty with child survival. The multidimensional poverty is measured in the dimension of knowledge, health and wealth and the child survival is measured with respect to infant mortality and under-five mortality. Descriptive statistics, principal component analyses and the life table methods are used in the analyses. Results The estimates of multidimensional poverty are robust and the inter-state differentials are large. While infant mortality rate and under-five mortality rate are disproportionately higher among the abject poor compared to the non-poor, there are no significant differences in child survival among educationally, economically and health poor at the national level. State pattern in child survival among the education, economical and health poor are mixed. Conclusion Use of multidimensional poverty measures help to identify abject poor who are unlikely to come out of poverty trap. The child survival is significantly lower among abject poor compared to moderate poor and non-poor. We urge to popularize the concept of multiple deprivations in research and program so as to reduce poverty and inequality in the population. PMID:22046384
Multidimensional stochastic approximation Monte Carlo.
Zablotskiy, Sergey V; Ivanov, Victor A; Paul, Wolfgang
2016-06-01
Stochastic Approximation Monte Carlo (SAMC) has been established as a mathematically founded powerful flat-histogram Monte Carlo method, used to determine the density of states, g(E), of a model system. We show here how it can be generalized for the determination of multidimensional probability distributions (or equivalently densities of states) of macroscopic or mesoscopic variables defined on the space of microstates of a statistical mechanical system. This establishes this method as a systematic way for coarse graining a model system, or, in other words, for performing a renormalization group step on a model. We discuss the formulation of the Kadanoff block spin transformation and the coarse-graining procedure for polymer models in this language. We also apply it to a standard case in the literature of two-dimensional densities of states, where two competing energetic effects are present g(E_{1},E_{2}). We show when and why care has to be exercised when obtaining the microcanonical density of states g(E_{1}+E_{2}) from g(E_{1},E_{2}). PMID:27415383
Multidimensional gene search with Genehopper
Munz, Matthias; Tönnies, Sascha; Balke, Wolf-Tilo; Simon, Eric
2015-01-01
The high abundance of genetic information enables researchers to gain new insights from the comparison of human genes according to their similarities. However, existing tools that allow the exploration of such gene-to-gene relationships, apply each similarity independently. To make use of multidimensional scoring, we developed a new search engine named Genehopper. It can handle two query types: (i) the typical use case starts with a term-to-gene search, i.e. an optimized full-text search for an anchor gene of interest. The web-interface can handle one or more terms including gene symbols and identifiers of Ensembl, UniProt, EntrezGene and RefSeq. (ii) When the anchor gene is defined, the user can explore its neighborhood by a gene-to-gene search as the weighted sum of nine normalized gene similarities based on sequence homology, protein domains, mRNA expression profiles, Gene Ontology Annotation, gene symbols and other features. Each weight can be adjusted by the user, allowing flexible customization of the gene search. All implemented similarities have a low pairwise correlation (max r2 = 0.4) implying a low linear dependency, i.e. any change in a single weight has an effect on the ranking. Thus, we treated them as separate dimensions in the search space. Genehopper is freely available at http://genehopper.ifis.cs.tu-bs.de. PMID:25990726
Multidimensional gene search with Genehopper.
Munz, Matthias; Tönnies, Sascha; Balke, Wolf-Tilo; Simon, Eric
2015-07-01
The high abundance of genetic information enables researchers to gain new insights from the comparison of human genes according to their similarities. However, existing tools that allow the exploration of such gene-to-gene relationships, apply each similarity independently. To make use of multidimensional scoring, we developed a new search engine named Genehopper. It can handle two query types: (i) the typical use case starts with a term-to-gene search, i.e. an optimized full-text search for an anchor gene of interest. The web-interface can handle one or more terms including gene symbols and identifiers of Ensembl, UniProt, EntrezGene and RefSeq. (ii) When the anchor gene is defined, the user can explore its neighborhood by a gene-to-gene search as the weighted sum of nine normalized gene similarities based on sequence homology, protein domains, mRNA expression profiles, Gene Ontology Annotation, gene symbols and other features. Each weight can be adjusted by the user, allowing flexible customization of the gene search. All implemented similarities have a low pairwise correlation (max r(2) = 0.4) implying a low linear dependency, i.e. any change in a single weight has an effect on the ranking. Thus, we treated them as separate dimensions in the search space. Genehopper is freely available at http://genehopper.ifis.cs.tu-bs.de. PMID:25990726
Multi-dimensional laser radars
NASA Astrophysics Data System (ADS)
Molebny, Vasyl; Steinvall, Ove
2014-06-01
We introduce the term "multi-dimensional laser radar", where the dimensions mean not only the coordinates of the object in space, but its velocity and orientation, parameters of the media: scattering, refraction, temperature, humidity, wind velocity, etc. The parameters can change in time and can be combined. For example, rendezvous and docking missions, autonomous planetary landing, along with laser ranging, laser altimetry, laser Doppler velocimetry, are thought to have aboard also the 3D ladar imaging. Operating in combinations, they provide more accurate and safer navigation, docking or landing, hazard avoidance capabilities. Combination with Doppler-based measurements provides more accurate navigation for both space and cruise missile applications. Critical is the information identifying the snipers based on combination of polarization and fluctuation parameters with data from other sources. Combination of thermal imaging and vibrometry can unveil the functionality of detected targets. Hyperspectral probing with laser reveals even more parameters. Different algorithms and architectures of ladar-based target acquisition, reconstruction of 3D images from point cloud, information fusion and displaying is discussed with special attention to the technologies of flash illumination and single-photon focal-plane-array detection.
Multidimensional model of cluster radioactivity
NASA Astrophysics Data System (ADS)
Denisov, V. Yu.
2013-10-01
The cluster decays 228Th→208Pb+20O, 232U→208Pb+24Ne, 236Pu→208Pb+28Mg, and 242Cm→208Pb+34Si are considered in the framework of the multidimensional cluster-preformation model. The macroscopic potential-energy surface related to the interaction between the cluster and the residue nucleus is evaluated in the framework of the nonlocal ℏ4 extended Thomas-Fermi approach with Skyrme and Coulomb forces. The shell correction to the macroscopic potential energy is also taken into account. The dynamical surface deformations of both the cluster and the residue nucleus are taken into consideration at the barrier penetration path. The heights of saddle points related to deformed nuclear shapes are lower than the barrier height between the spherical cluster and residue nuclei; therefore the dynamical deformations of nuclei increase the barrier penetrability and reduce the half-life of cluster decay. The shell-correction contribution into the potential energy between cluster and residue nucleus is important for both the potential landscape and the half-life evaluation. The experimental values of cluster-decay half-lives are well reproduced in the model.
Multidimensional stochastic approximation Monte Carlo
NASA Astrophysics Data System (ADS)
Zablotskiy, Sergey V.; Ivanov, Victor A.; Paul, Wolfgang
2016-06-01
Stochastic Approximation Monte Carlo (SAMC) has been established as a mathematically founded powerful flat-histogram Monte Carlo method, used to determine the density of states, g (E ) , of a model system. We show here how it can be generalized for the determination of multidimensional probability distributions (or equivalently densities of states) of macroscopic or mesoscopic variables defined on the space of microstates of a statistical mechanical system. This establishes this method as a systematic way for coarse graining a model system, or, in other words, for performing a renormalization group step on a model. We discuss the formulation of the Kadanoff block spin transformation and the coarse-graining procedure for polymer models in this language. We also apply it to a standard case in the literature of two-dimensional densities of states, where two competing energetic effects are present g (E1,E2) . We show when and why care has to be exercised when obtaining the microcanonical density of states g (E1+E2) from g (E1,E2) .
NASA Astrophysics Data System (ADS)
Newton, Isaac; Henry, Richard Conn
2000-07-01
An extraordinarily simple and transparent derivation of the formula for the acceleration that occurs in uniform circular motion is presented, and is advocated for use in high school and college freshman physics textbooks.
NASA Technical Reports Server (NTRS)
Kolenkiewicz, R.
1973-01-01
Tracking of the Beacon Explorer-C satellite by a precision laser system was used to measure the polar motion and solid earth tide. The tidal perturbation of satellite latitude is plotted as variation in maximum latitude in seconds of arc on earth's surface as a function of the date, and polar motion is shown by plotting the variation in latitude of the laser in seconds of arc along the earth's surface as a function of date
Improved multidimensional semiclassical tunneling theory.
Wagner, Albert F
2013-12-12
We show that the analytic multidimensional semiclassical tunneling formula of Miller et al. [Miller, W. H.; Hernandez, R.; Handy, N. C.; Jayatilaka, D.; Willets, A. Chem. Phys. Lett. 1990, 172, 62] is qualitatively incorrect for deep tunneling at energies well below the top of the barrier. The origin of this deficiency is that the formula uses an effective barrier weakly related to the true energetics but correctly adjusted to reproduce the harmonic description and anharmonic corrections of the reaction path at the saddle point as determined by second order vibrational perturbation theory. We present an analytic improved semiclassical formula that correctly includes energetic information and allows a qualitatively correct representation of deep tunneling. This is done by constructing a three segment composite Eckart potential that is continuous everywhere in both value and derivative. This composite potential has an analytic barrier penetration integral from which the semiclassical action can be derived and then used to define the semiclassical tunneling probability. The middle segment of the composite potential by itself is superior to the original formula of Miller et al. because it incorporates the asymmetry of the reaction barrier produced by the known reaction exoergicity. Comparison of the semiclassical and exact quantum tunneling probability for the pure Eckart potential suggests a simple threshold multiplicative factor to the improved formula to account for quantum effects very near threshold not represented by semiclassical theory. The deep tunneling limitations of the original formula are echoed in semiclassical high-energy descriptions of bound vibrational states perpendicular to the reaction path at the saddle point. However, typically ab initio energetic information is not available to correct it. The Supporting Information contains a Fortran code, test input, and test output that implements the improved semiclassical tunneling formula. PMID:24224758
Image demodulation using multidimensional energy separation
NASA Astrophysics Data System (ADS)
Maragos, Petros; Bovik, Alan C.
1995-09-01
Locally narrow-band images can be modeled as two-dimensional (2D) spatial AM-FM signals with several applications in image texture analysis and computer vision. We formulate an image-demodulation problem and present a solution based on the multidimensional energy operator Phi (f)= \\double-vertical-bar \\inverted-Delta-triangle f \\double-vertical-bar 2-f \\inverted-Delta-triangle 2 f . This nonlinear operator is a multidimensional extension of the one-dimensional (1D) energy-tracking operator Psi (f)=( f\\prime)2 -ff\\prime\\prime , which has been found useful for demodulating 1D AM-FM and speech signals. We discuss some interesting properties of the multidimensional operator and develop a multidimensional energy-separation algorithm to estimate the amplitude envelope and instantaneous frequencies of 2D spatially varying AM-FM signals. Experiments are also presented on applying this 2D energy-demodulation algorithm to estimate the instantaneous amplitude contrast and spatial frequencies of image textures bandpass filtered by means of Gabor filters. The attractive features of the multidimensional energy operator and the 2D energy-separation algorithm are their simplicity, efficiency, and ability to track instantaneously varying
A proposed multidimensional analysis function
NASA Astrophysics Data System (ADS)
Knight, Byron F.; Hamilton, Mark K.
2003-08-01
Previous work has suggested a potential value in the combination of physical property data types (e.g. magnetic and terrain slope) when searching for oil and mineral deposits. This work studies a notional multi-dimensional function to determine the likelihood of finding such deposits. Additionally, this hypothesis assumes some basic requirements must be meet in order to validate this function. The standard for determining the value of commercially gathered electro optical imagery is the same as with any optical system -- the ability to determine object in the field of view. Further, this function is defined as the ability to determine the presence of two parallel lines, vice only one. The National Imagery and Mapping Agency (NIMA) uses a function called Digital Terrain Elevation Data (DTED) to determine the elevation within a field of view. The DTED values for each pixel within a digital, commercial image can be considered similar to a gradient, whereby higher values are merely higher elevations. For the commercial electro optical system IKONOS (owned by Space Imaging, Inc.), the "resolution" is commonly referred to as 1 meter, which is the least discernable, parallel-line, separation distance. This hypothesis uses gravity and magnetic data to augment the DTED "gradient". As with the terrain values on the earth, gravity and magnetic values are continuously changing. Further, they can change for various reasons. Both are greatly affected by the changes in the subsurface materials, or the density of the soil and metallic content (e.g. iron). It is precisely these variations, through the combination of such differing forms of data, which can help determine the presence of oil and mineral deposits. The core of this work is a notional function development. Previous peer review has rightly pointed out that data fusion principles state that data must be commensurable before it can be fused. This work does not attempt to redefine data fusion concepts, but merely establish
Fast adaptive estimation of multidimensional psychometric functions.
DiMattina, Christopher
2015-01-01
Recently in vision science there has been great interest in understanding the perceptual representations of complex multidimensional stimuli. Therefore, it is becoming very important to develop methods for performing psychophysical experiments with multidimensional stimuli and efficiently estimating psychometric models that have multiple free parameters. In this methodological study, I analyze three efficient implementations of the popular Ψ method for adaptive data collection, two of which are novel approaches to psychophysical experiments. Although the standard implementation of the Ψ procedure is intractable in higher dimensions, I demonstrate that my implementations generalize well to complex psychometric models defined in multidimensional stimulus spaces and can be implemented very efficiently on standard laboratory computers. I show that my implementations may be of particular use for experiments studying how subjects combine multiple cues to estimate sensory quantities. I discuss strategies for speeding up experiments and suggest directions for future research in this rapidly growing area at the intersection of cognitive science, neuroscience, and machine learning. PMID:26200886
NASA Astrophysics Data System (ADS)
Sykes, Mary V.; Moynihan, P. Daniel
1996-12-01
Equations are derived which describe the apparent motion of an asteroid traveling on an elliptical orbit in geocentric ecliptic coordinates. At opposition, the equations are identical to those derived by Bowellet al. (Bowell, E., B. Skiff, and L. Wasserman 1990. InAsteroids, Comets, Meteors III(C.-I. Lagerkvist, M. Rickman, B. A. Lindblad, and M. Lindgren, Eds.), pp. 19-24. Uppsala Universitet, Uppsala, Sweden). These equations can be an important component in the optimization of search strategies for specific asteroid populations based on their apparent motions relative to other populations when observed away from opposition.
... Homework? Here's Help White House Lunch Recipes What's Motion Sickness? KidsHealth > For Kids > What's Motion Sickness? Print ... motion sickness might get even worse. continue Avoiding Motion Sickness To avoid motion sickness: Put your best ...
ERIC Educational Resources Information Center
Lavenda, Bernard H.
1985-01-01
Explains the phenomenon of Brownian motion, which serves as a mathematical model for random processes. Topics addressed include kinetic theory, Einstein's theory, particle displacement, and others. Points out that observations of the random course of a particle suspended in fluid led to the first accurate measurement of atomic mass. (DH)
The Efficacy of Multidimensional Constraint Keys in Database Query Performance
ERIC Educational Resources Information Center
Cardwell, Leslie K.
2012-01-01
This work is intended to introduce a database design method to resolve the two-dimensional complexities inherent in the relational data model and its resulting performance challenges through abstract multidimensional constructs. A multidimensional constraint is derived and utilized to implement an indexed Multidimensional Key (MK) to abstract a…
Ultrafast multidimensional Laplace NMR for a rapid and sensitive chemical analysis
NASA Astrophysics Data System (ADS)
Ahola, Susanna; Zhivonitko, Vladimir V.; Mankinen, Otto; Zhang, Guannan; Kantola, Anu M.; Chen, Hsueh-Ying; Hilty, Christian; Koptyug, Igor V.; Telkki, Ville-Veikko
2015-09-01
Traditional nuclear magnetic resonance (NMR) spectroscopy relies on the versatile chemical information conveyed by spectra. To complement conventional NMR, Laplace NMR explores diffusion and relaxation phenomena to reveal details on molecular motions. Under a broad concept of ultrafast multidimensional Laplace NMR, here we introduce an ultrafast diffusion-relaxation correlation experiment enhancing the resolution and information content of corresponding 1D experiments as well as reducing the experiment time by one to two orders of magnitude or more as compared with its conventional 2D counterpart. We demonstrate that the method allows one to distinguish identical molecules in different physical environments and provides chemical resolution missing in NMR spectra. Although the sensitivity of the new method is reduced due to spatial encoding, the single-scan approach enables one to use hyperpolarized substances to boost the sensitivity by several orders of magnitude, significantly enhancing the overall sensitivity of multidimensional Laplace NMR.
Ultrafast multidimensional Laplace NMR for a rapid and sensitive chemical analysis
Ahola, Susanna; Zhivonitko, Vladimir V; Mankinen, Otto; Zhang, Guannan; Kantola, Anu M.; Chen, Hsueh-Ying; Hilty, Christian; Koptyug, Igor V.; Telkki, Ville-Veikko
2015-01-01
Traditional nuclear magnetic resonance (NMR) spectroscopy relies on the versatile chemical information conveyed by spectra. To complement conventional NMR, Laplace NMR explores diffusion and relaxation phenomena to reveal details on molecular motions. Under a broad concept of ultrafast multidimensional Laplace NMR, here we introduce an ultrafast diffusion-relaxation correlation experiment enhancing the resolution and information content of corresponding 1D experiments as well as reducing the experiment time by one to two orders of magnitude or more as compared with its conventional 2D counterpart. We demonstrate that the method allows one to distinguish identical molecules in different physical environments and provides chemical resolution missing in NMR spectra. Although the sensitivity of the new method is reduced due to spatial encoding, the single-scan approach enables one to use hyperpolarized substances to boost the sensitivity by several orders of magnitude, significantly enhancing the overall sensitivity of multidimensional Laplace NMR. PMID:26381101
The Multidimensional Curriculum Model (MdCM)
ERIC Educational Resources Information Center
Vidergor, Hava E.
2010-01-01
The multidimensional Curriculum Model (MdCM) helps teachers to better prepare gifted and able students for our changing world, acquiring much needed skills. It is influenced by general learning theory of constructivism, notions of preparing students for 21st century, Teaching the Future Model, and current comprehensive curriculum models for…
Stability of Adolescents' Multidimensional Life Satisfaction Reports
ERIC Educational Resources Information Center
Antaramian, Susan P.; Huebner, E. Scott
2009-01-01
Eighty-four students were administered the Multidimensional Students' Life Satisfaction Scale (MSLSS) on three occasions, 1 year apart (Grades 8, 9, and 10). The 1-year stability coefficients ranged from 0.29 to 0.59, whereas the 2-year stability coefficients ranged from 0.41 to 0.59. MSLSS mean scores were consistent across administrations, with…
Longitudinal Network Analysis Using Multidimensional Scaling.
ERIC Educational Resources Information Center
Barnett, George A.; Palmer, Mark T.
The Galileo System, a variant of metric multidimensional scaling, is used in this paper to analyze over-time changes in social networks. The paper first discusses the theoretical necessity for the use of this procedure and the methodological problems associated with its use. It then examines the air traffic network among 31 major cities in the…
Taylor approximations of multidimensional linear differential systems
NASA Astrophysics Data System (ADS)
Lomadze, Vakhtang
2016-06-01
The Taylor approximations of a multidimensional linear differential system are of importance as they contain a complete information about it. It is shown that in order to construct them it is sufficient to truncate the exponential trajectories only. A computation of the Taylor approximations is provided using purely algebraic means, without requiring explicit knowledge of the trajectories.
Multidimensional Human Dynamics in Mobile Phone Communications
Quadri, Christian; Zignani, Matteo; Capra, Lorenzo; Gaito, Sabrina; Rossi, Gian Paolo
2014-01-01
In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process. PMID:25068479
Multidimensional Treatment of Fear of Death.
ERIC Educational Resources Information Center
Hoelter, Jon W.
1979-01-01
Presents a multidimensional conception of fear of death and provides subscales for measuring suggested dimensions (fear of the dying process, of the dead, of being destroyed, for significant others, of the unknown, of conscious death, for body after death, and of premature death). Evidence for construct validity is provided. (Author/BEF)
CAMS: OLAPing Multidimensional Data Streams Efficiently
NASA Astrophysics Data System (ADS)
Cuzzocrea, Alfredo
In the context of data stream research, taming the multidimensionality of real-life data streams in order to efficiently support OLAP analysis/mining tasks is a critical challenge. Inspired by this fundamental motivation, in this paper we introduce
Multidimensional Scaling for Measuring Alcohol Expectancies.
ERIC Educational Resources Information Center
Rather, Bruce; And Others
Although expectancies for alcohol have been shown to influence drinking behavior, current expectancy questionnaires do not lend themselves to the study of how expectancies are represented in memory. Two studies were conducted which utilized multidimensional scaling techniques designed to produce hypothesized representations of cognitive…
Bilingual Creativity, Multidimensional Analysis, and World Englishes.
ERIC Educational Resources Information Center
Baker, Wendy; Eggington, William G.
1999-01-01
Using Biber's multidimensional analysis (1998) to examine a large corpus of world English literatures written in Indian, West African, British, Anglo-American, and Mexican-American varieties of English, examines whether quantitative analyses can also be insightful and useful in the examination of world Englishes literatures in expanding…
Multidimensional NMR spectroscopy in a single scan.
Gal, Maayan; Frydman, Lucio
2015-11-01
Multidimensional NMR has become one of the most widespread spectroscopic tools available to study diverse structural and functional aspects of organic and biomolecules. A main feature of multidimensional NMR is the relatively long acquisition times that these experiments demand. For decades, scientists have been working on a variety of alternatives that would enable NMR to overcome this limitation, and deliver its data in shorter acquisition times. Counting among these methodologies is the so-called ultrafast (UF) NMR approach, which in principle allows one to collect arbitrary multidimensional correlations in a single sub-second transient. By contrast to conventional acquisitions, a main feature of UF NMR is a spatiotemporal manipulation of the spins that imprints the chemical shift and/or J-coupling evolutions being sought, into a spatial pattern. Subsequent gradient-based manipulations enable the reading out of this information and its multidimensional correlation into patterns that are identical to those afforded by conventional techniques. The current review focuses on the fundamental principles of this spatiotemporal UF NMR manipulation, and on a few of the methodological extensions that this form of spectroscopy has undergone during the years. PMID:26249041
Multidimensional Perspectives on Principal Leadership Effectiveness
ERIC Educational Resources Information Center
Beycioglu, Kadir, Ed.; Pashiardis, Petros, Ed.
2015-01-01
Exceptional management skills are crucial to success in educational environments. As school leaders, principals are expected to effectively supervise the school system while facing a multitude of issues and demands. "Multidimensional Perspectives on Principal Leadership Effectiveness" combines best practices and the latest approaches in…
Multidimensional human dynamics in mobile phone communications.
Quadri, Christian; Zignani, Matteo; Capra, Lorenzo; Gaito, Sabrina; Rossi, Gian Paolo
2014-01-01
In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process. PMID:25068479
Multidimensional Scaling Applied to Linguistic Relationships.
ERIC Educational Resources Information Center
Black, Paul
1973-01-01
As the several specific applications in this paper demonstrate, multidimensional scaling provides a long-needed means for investigating and describing spatial relationships among speech varieties. It is especially applicable to the relationships among varieties of a single language (or more properly, linguistic "cline"), which, as is generally…
Uncertainty of Comparative Judgments and Multidimensional Structure
ERIC Educational Resources Information Center
Sjoberg, Lennart
1975-01-01
An analysis of preferences with respect to silhouette drawings of nude females is presented. Systematic intransitivities were discovered. The dispersions of differences (comparatal dispersons) were shown to reflect the multidimensional structure of the stimuli, a finding expected on the basis of prior work. (Author)
Unidimensional Interpretations for Multidimensional Test Items
ERIC Educational Resources Information Center
Kahraman, Nilufer
2013-01-01
This article considers potential problems that can arise in estimating a unidimensional item response theory (IRT) model when some test items are multidimensional (i.e., show a complex factorial structure). More specifically, this study examines (1) the consequences of model misfit on IRT item parameter estimates due to unintended minor item-level…
Multidimensional Screening as a Pharmacology Laboratory Experience.
ERIC Educational Resources Information Center
Malone, Marvin H.; And Others
1979-01-01
A multidimensional pharmacodynamic screening experiment that addresses drug interaction is included in the pharmacology-toxicology laboratory experience of pharmacy students at the University of the Pacific. The student handout with directions for the procedure is reproduced, drug compounds tested are listed, and laboratory evaluation results are…
Multidimensional wave field signal theory: Mathematical foundations
NASA Astrophysics Data System (ADS)
Baddour, Natalie
2011-06-01
Many important physical phenomena are described by wave or diffusion-wave type equations. Since these equations are linear, it would be useful to be able to use tools from the theory of linear signals and systems in solving related forward or inverse problems. In particular, the transform domain signal description from linear system theory has shown concrete promise for the solution of problems that are governed by a multidimensional wave field. The aim is to develop a unified framework for the description of wavefields via multidimensional signals. However, certain preliminary mathematical results are crucial for the development of this framework. This first paper on this topic thus introduces the mathematical foundations and proves some important mathematical results. The foundation of the framework starts with the inhomogeneous Helmholtz or pseudo-Helmholtz equation, which is the mathematical basis of a large class of wavefields. Application of the appropriate multi-dimensional Fourier transform leads to a transfer function description. To return to the physical spatial domain, certain mathematical results are necessary and these are presented and proved here as six fundamental theorems. These theorems are crucial for the evaluation of a certain class of improper integrals which arise in the evaluation of inverse multi-dimensional Fourier and Hankel transforms, upon which the framework is based. Subsequently, applications of these theorems are demonstrated, in particular for the derivation of Green's functions in different coordinate systems.
Multidimensional IRT Models for Composite Scores
ERIC Educational Resources Information Center
Yen, Shu Jing; Walker, Leah
2007-01-01
Tests of English Language Proficiency are often designed such that each section of the test measures a single latent ability. For instance an English Proficiency Assessment might consist of sections measuring Speaking, Listening, and Reading ability. However, Overall English Proficiency and composite abilities are naturally multidimensional. This…
A New Heterogeneous Multidimensional Unfolding Procedure
ERIC Educational Resources Information Center
Park, Joonwook; Rajagopal, Priyali; DeSarbo, Wayne S.
2012-01-01
A variety of joint space multidimensional scaling (MDS) methods have been utilized for the spatial analysis of two- or three-way dominance data involving subjects' preferences, choices, considerations, intentions, etc. so as to provide a parsimonious spatial depiction of the underlying relevant dimensions, attributes, stimuli, and/or subjects'…
A Multidimensional Model of Adolescent Drug Involvement.
ERIC Educational Resources Information Center
Herting, Jerald R.; And Others
1996-01-01
Tested a multidimensional model of adolescent drug involvement on samples of high school students. Focused on five first-order dimensions: drug access, alcohol use, other drug use, drug control problems, and adverse drug use consequences. Results contributed to understanding differences and change in drug involvement among high-risk versus…
Determining Factor Structure in a Multidimensional Inventory.
ERIC Educational Resources Information Center
Deeter, Thomas E.; Gill, Diane L.
A two-step procedure is described and used to revise a multidimensional inventory in its developmental stages. First, the latent factors influencing the observed variables on the inventory are determined and justified using the following five methods: Kaiser's criterion, root staring, examination of difference values, examination of root mean…
Multidimensional Directed Phase Analysis for Basic Rhythm of EEG
NASA Astrophysics Data System (ADS)
Sakata, Osamu; Shiina, Tsuyoshi; Saito, Yoichi
In this paper, multidimensional directed phase analysis is proposed as a means of causality analysis for multiple time series, is proposed. The multidimensional directed phase is a phase with causality, which is associated with multidimensional directed coherence. Using multidimensional directed phase analysis, direction and time of a signal flow among multidimensional time series can be estimated. In two simulations, artificial time series have been analyzed by the new method to confirm its characteristics. In first simulation, accuracy of estimation of signal flow time has been investigated. Second, a complex signal flow pattern has been analyzed. Next, the multidimensional directed phase analysis and the multidimensional directed coherence analysis have been applied to EEG data of normal volunteer. As a result, we have got information differ from common learning which is the difference between the phase of a frontal alpha waves and an occipital is π.
Research Burnout: a refined multidimensional scale.
Singh, Surendra N; Dalal, Nikunj; Mishra, Sanjay
2004-12-01
In a prevailing academic climate where there are high expectations for faculty to publish and generate grants, the exploration of Research Burnout among higher education faculty has become increasingly important. Unfortunately, it is a topic that has not been well researched empirically. In 1997 Singh and Bush developed a unidimensional scale to measure Research Burnout. A closer inspection of the definition of this construct and the composition of its items suggests, however, that the construct may be multidimensional and analogous to Maslach's Psychological Burnout Scale. In this paper, we propose a refined, multidimensional Research Burnout scale and test its factorial validity using confirmatory factor analysis. The nomological validity of this refined scale is established by examining hypothesized relationships between Research Burnout and other constructs such as Intrinsic Motivation for doing research, Extrinsic Pressures to do research, and Knowledge Obsolescence. PMID:15762409
Elements Of Theory Of Multidimensional Complex Variables
NASA Technical Reports Server (NTRS)
Martin, E. Dale
1993-01-01
Two reports describe elements of theory of multidimensional complex variables, with emphasis on three dimensions. First report introduces general theory. Second, presents further developments in theory of analytic functions of single three-dimensional variable and applies theory to representation of ideal flows. Results of preliminary studies suggest analytic functions of new three-dimensional complex variables useful in numerous applications, including representing of three-dimensional flows and potentials.
Multidimensional reaction rate theory with anisotropic diffusion
NASA Astrophysics Data System (ADS)
Berezhkovskii, Alexander M.; Szabo, Attila; Greives, Nicholas; Zhou, Huan-Xiang
2014-11-01
An analytical expression is derived for the rate constant that describes diffusive transitions between two deep wells of a multidimensional potential. The expression, in contrast to the Kramers-Langer formula for the rate constant, is valid even when the diffusion is highly anisotropic. Our approach is based on a variational principle for the reactive flux and uses a trial function for the splitting probability or commitor. The theoretical result is validated by Brownian dynamics simulations.
Trellis coding with multidimensional QAM signal sets
NASA Technical Reports Server (NTRS)
Pietrobon, Steven S.; Costello, Daniel J.
1993-01-01
Trellis coding using multidimensional QAM signal sets is investigated. Finite-size 2D signal sets are presented that have minimum average energy, are 90-deg rotationally symmetric, and have from 16 to 1024 points. The best trellis codes using the finite 16-QAM signal set with two, four, six, and eight dimensions are found by computer search (the multidimensional signal set is constructed from the 2D signal set). The best moderate complexity trellis codes for infinite lattices with two, four, six, and eight dimensions are also found. The minimum free squared Euclidean distance and number of nearest neighbors for these codes were used as the selection criteria. Many of the multidimensional codes are fully rotationally invariant and give asymptotic coding gains up to 6.0 dB. From the infinite lattice codes, the best codes for transmitting J, J + 1/4, J + 1/3, J + 1/2, J + 2/3, and J + 3/4 bit/sym (J an integer) are presented.
Multidimensional Plasma Sheaths over Electrically Inhomogeneous Surfaces
NASA Astrophysics Data System (ADS)
Economou, Demetre
2004-09-01
Multidimensional plasma sheaths are encountered in a number of applications including plasma immersion ion implantation, extraction of ions (or plasma) through grids, MEMS fabrication, neutral beam sources, and plasma in contact with internal reactor parts (e.g., wafer chuck edge). The sheath may be multidimensional when: (a) plasma is in contact with surface topography, and the size of the topographical features is comparable to or larger than the plasma sheath thickness, or (b) the surface is flat but inhomogeneous, i.e., a conducting surface next to an insulating surface. In either case, the flux, energy and angular distributions of energetic species incident on the substrate are of primary importance. These quantities depend critically on the shape of the meniscus (plasma-sheath boundary) formed over the surface. A two-dimensional fluid/Monte Carlo simulation model was developed to study multidimensional sheaths. The radio frequency (RF) sheath potential evolution, and ion density and flux profiles over the surface were predicted with a self-consistent fluid simulation. The trajectories of ions and energetic neutrals (resulting by ion neutralization on surfaces or charge exchange collisions in the gas phase) were then followed with a Monte Carlo simulation. Ion flow and energy and angular distributions of ions bombarding a flat but electrically inhomogeneous surface will be reported in detail. Ion flow over trenches and holes will also be reported. Work supported by the NSF, Sandia National Laboratories and NIST.
NASA Technical Reports Server (NTRS)
1993-01-01
MOOG, Inc. supplies hydraulic actuators for the Space Shuttle. When MOOG learned NASA was interested in electric actuators for possible future use, the company designed them with assistance from Marshall Space Flight Center. They also decided to pursue the system's commercial potential. This led to partnership with InterActive Simulation, Inc. for production of cabin flight simulators for museums, expositions, etc. The resulting products, the Magic Motion Simulator 30 Series, are the first electric powered simulators. Movements are computer-guided, including free fall to heighten the sense of moving through space. A projection system provides visual effects, and the 11 speakers of a digital laser based sound system add to the realism. The electric actuators are easier to install, have lower operating costs, noise, heat and staff requirements. The U.S. Space & Rocket Center and several other organizations have purchased the simulators.
Multidimensional bit-rate control for video communication
NASA Astrophysics Data System (ADS)
Reed, Eric C.; Lim, Jae S.
2000-12-01
In conventional bit rate control schemes, the buffer level is controlled by adjusting the quantization step size while the frame rate and spatial resolution chosen for coding are fixed throughout the coding process. In this paper, we consider a more general Multidimensional (M-D) bit rate control where the frame rate, spatial resolution and quantization step size are jointly adapted for buffer control. In the M-D bit rate control setting, the problem is to decide which frames to code (and which frames to skip) along with the spatial resolution and the quantization step size to use for each coded frame. Given a finite set of operating points on a M-D grid, we formulate the optimal solution of the M-D buffer-constrained allocation problem. The formulation allows a skipped frame to be reconstructed from one coded frame using any temporal interpolation method. A dynamic programming algorithm is presented to obtain an optimal solution for the case of intraframe coding which is a special case of dependent coding. We experiment with both zero-order hold and motion-compensated temporal interpolation. Operational rate-distortion (R-D) bounds are illustrated for both the M-D and conventional bit rate control approaches. Our focus is one very low bit rate applications where a significant delay is tolerable.
NASA Astrophysics Data System (ADS)
Vicsek, Tamás; Zafeiris, Anna
2012-08-01
We review the observations and the basic laws describing the essential aspects of collective motion - being one of the most common and spectacular manifestation of coordinated behavior. Our aim is to provide a balanced discussion of the various facets of this highly multidisciplinary field, including experiments, mathematical methods and models for simulations, so that readers with a variety of background could get both the basics and a broader, more detailed picture of the field. The observations we report on include systems consisting of units ranging from macromolecules through metallic rods and robots to groups of animals and people. Some emphasis is put on models that are simple and realistic enough to reproduce the numerous related observations and are useful for developing concepts for a better understanding of the complexity of systems consisting of many simultaneously moving entities. As such, these models allow the establishing of a few fundamental principles of flocking. In particular, it is demonstrated, that in spite of considerable differences, a number of deep analogies exist between equilibrium statistical physics systems and those made of self-propelled (in most cases living) units. In both cases only a few well defined macroscopic/collective states occur and the transitions between these states follow a similar scenario, involving discontinuity and algebraic divergences.
Nuclear Forensic Inferences Using Iterative Multidimensional Statistics
Robel, M; Kristo, M J; Heller, M A
2009-06-09
Nuclear forensics involves the analysis of interdicted nuclear material for specific material characteristics (referred to as 'signatures') that imply specific geographical locations, production processes, culprit intentions, etc. Predictive signatures rely on expert knowledge of physics, chemistry, and engineering to develop inferences from these material characteristics. Comparative signatures, on the other hand, rely on comparison of the material characteristics of the interdicted sample (the 'questioned sample' in FBI parlance) with those of a set of known samples. In the ideal case, the set of known samples would be a comprehensive nuclear forensics database, a database which does not currently exist. In fact, our ability to analyze interdicted samples and produce an extensive list of precise materials characteristics far exceeds our ability to interpret the results. Therefore, as we seek to develop the extensive databases necessary for nuclear forensics, we must also develop the methods necessary to produce the necessary inferences from comparison of our analytical results with these large, multidimensional sets of data. In the work reported here, we used a large, multidimensional dataset of results from quality control analyses of uranium ore concentrate (UOC, sometimes called 'yellowcake'). We have found that traditional multidimensional techniques, such as principal components analysis (PCA), are especially useful for understanding such datasets and drawing relevant conclusions. In particular, we have developed an iterative partial least squares-discriminant analysis (PLS-DA) procedure that has proven especially adept at identifying the production location of unknown UOC samples. By removing classes which fell far outside the initial decision boundary, and then rebuilding the PLS-DA model, we have consistently produced better and more definitive attributions than with a single pass classification approach. Performance of the iterative PLS-DA method
Multidimensional voice analysis of reflux laryngitis patients.
Pribuisienë, Rûta; Uloza, Virgilijus; Saferis, Viktoras
2005-01-01
The aim of the study was to analyze and quantify the voice characteristics of reflux laryngitis (RL) patients and to determine the most important voice tests and voice-quality parameters in the functional diagnostics of RL. The voices of 83 RL patients and 31 persons in the control group were evaluated. Vocal function was assessed using a multidimensional set of video laryngostroboscopic, perceptual, acoustic, aerodynamic and subjective measurements according to the protocol elaborated by the Committee on Phoniatrics of the European Laryngological Society. The mean values of the hoarseness visual analogue scale assessment and voice handicap index were significantly higher (P<0.05) in the group of RL patients as compared to the controls. Objective voice assessment revealed a significant increase in mean values of jitter, shimmer and normalized noise energy (NNE), along with a significant decrease in pitch range, maximum frequency, phonetogram area (S) and maximum phonation time (MPT) in RL patients, both in the male and female subgroups. According to the results of discriminant analysis, the NNE, MPT, S and intensity range were determined as an optimum set for functional diagnostics of RL. The derived function (equation) makes it possible to assign the person to the group of RL patients with an accuracy of 86.7%. The sensitivity and specificity of eight voice parameters were found to be higher than 50%. The results of the present study demonstrate a reduction of phonation capabilities and voice quality in RL patients. Multidimensional voice evaluation makes it possible to detect significant differences in mean values of perceptual, subjective and objective voice quality parameters between RL patients and controls groups. Therefore, multidimensional voice analysis is an important tool in the functional diagnostics of RL. PMID:15004705
Palmprint based multidimensional fuzzy vault scheme.
Liu, Hailun; Sun, Dongmei; Xiong, Ke; Qiu, Zhengding
2014-01-01
Fuzzy vault scheme (FVS) is one of the most popular biometric cryptosystems for biometric template protection. However, error correcting code (ECC) proposed in FVS is not appropriate to deal with real-valued biometric intraclass variances. In this paper, we propose a multidimensional fuzzy vault scheme (MDFVS) in which a general subspace error-tolerant mechanism is designed and embedded into FVS to handle intraclass variances. Palmprint is one of the most important biometrics; to protect palmprint templates; a palmprint based MDFVS implementation is also presented. Experimental results show that the proposed scheme not only can deal with intraclass variances effectively but also could maintain the accuracy and meanwhile enhance security. PMID:24892094
Evolution of multidimensional flat anisotropic cosmological models
Beloborodov, A. ); Demianski, M. Nicolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw International Center for Relativistic Astrophysics , Universita di Roma I, La Sapienza, Rome ); Ivanov, P.; Polnarev, A.G. )
1993-07-15
We study the dynamics of a flat multidimensional anisotropic cosmological model filled with an anisotropic fluidlike medium. By an appropriate choice of variables, the dynamical equations reduce to a two-dimensional dynamical system. We present a detailed analysis of the time evolution of this system and the conditions of the existence of spacetime singularities. We investigate the conditions under which violent, exponential, and power-law inflation is possible. We show that dimensional reduction cannot proceed by anti-inflation (rapid contraction of internal space). Our model indicates that it is very difficult to achieve dimensional reduction by classical means.
A multidimensional representation model of geographic features
Usery, E. Lynn; Timson, George; Coletti, Mark
2016-01-01
A multidimensional model of geographic features has been developed and implemented with data from The National Map of the U.S. Geological Survey. The model, programmed in C++ and implemented as a feature library, was tested with data from the National Hydrography Dataset demonstrating the capability to handle changes in feature attributes, such as increases in chlorine concentration in a stream, and feature geometry, such as the changing shoreline of barrier islands over time. Data can be entered directly, from a comma separated file, or features with attributes and relationships can be automatically populated in the model from data in the Spatial Data Transfer Standard format.
Palmprint Based Multidimensional Fuzzy Vault Scheme
Liu, Hailun; Sun, Dongmei; Xiong, Ke; Qiu, Zhengding
2014-01-01
Fuzzy vault scheme (FVS) is one of the most popular biometric cryptosystems for biometric template protection. However, error correcting code (ECC) proposed in FVS is not appropriate to deal with real-valued biometric intraclass variances. In this paper, we propose a multidimensional fuzzy vault scheme (MDFVS) in which a general subspace error-tolerant mechanism is designed and embedded into FVS to handle intraclass variances. Palmprint is one of the most important biometrics; to protect palmprint templates; a palmprint based MDFVS implementation is also presented. Experimental results show that the proposed scheme not only can deal with intraclass variances effectively but also could maintain the accuracy and meanwhile enhance security. PMID:24892094
Multidimensional modelling of classical pulsating stars
NASA Astrophysics Data System (ADS)
Muthsam, H. J.; Kupka, F.
2016-05-01
After an overview of general aspects of modelling the pulsation- convection interaction we present reasons why such simulations (in multidimensions) are needed but, at the same time, pose a considerable challenge. We then discuss, for several topics, what insights multidimensional simulations have either already provided or can be expected to yield in the future. We finally discuss properties of our ANTARES code. Many of these features can be expected to be characteristic of other codes which may possibly be applied to these physical questions in the foreseeable future.
Multidimensional world, inflation, and modern acceleration
Bronnikov, K. A.; Rubin, S. G.; Svadkovsky, I. V.
2010-04-15
Starting from pure multidimensional gravity with curvature-nonlinear terms but no matter fields in the initial action, we obtain a cosmological model with two effective scalar fields related to the size of two extra factor spaces. The model includes both an early inflationary stage and that of modern accelerated expansion and satisfies the observational data. There are no small parameters; the effective inflaton mass depends on the initial conditions which explain its small value as compared to the Planck mass. At the modern stage, the size of extra dimensions slowly increases, therefore this model predicts drastic changes in the physical laws of our Universe in the remote future.
Multidimensional visualization and browsing for intelligence analysis
Crow, V.; Pottier, M.; Thomas, J.
1994-09-01
Visualization tools have been invaluable in the process of scientific discovery by providing researchers with insights gained through graphical tools and techniques. At PNL, the Multidimensional Visualization and Advanced Browsing (MVAB) project is extending visualization technology to the problems of intelligence analysis of textual documents by creating spatial representations of textual information. By representing an entire corpus of documents as points in a coordinate space of two or more dimensions, the tools developed by the MVAB team give the analyst the ability to quickly browse the entire document base and determine relationships among documents and publication patterns not readily discernible through traditional lexical means.
NASA Astrophysics Data System (ADS)
Jansen, Christian H. P.; Arigovindan, Muthuvel; Suhling, Michael; Marsch, Stefan; Unser, Michael A.; Hunziker, Patrick
2003-05-01
We present a new wavelet-based strategy for autonomous feature extraction and segmentation of cardiac structures in dynamic ultrasound images. Image sequences subjected to a multidimensional (2D plus time) wavelet transform yield a large number of individual subbands, each coding for partial structural and motion information of the ultrasound sequence. We exploited this fact to create an analysis strategy for autonomous analysis of cardiac ultrasound that builds on shape- and motion specific wavelet subband filters. Subband selection was in an automatic manner based on subband statistics. Such a collection of predefined subbands corresponds to the so-called footprint of the target structure and can be used as a multidimensional multiscale filter to detect and localize the target structure in the original ultrasound sequence. Autonomous, unequivocal localization by the autonomous algorithm is then done using a peak finding algorithm, allowing to compare the findings with a reference standard. Image segmentation is then possible using standard region growing operations. To test the feasibility of this multiscale footprint algorithm, we tried to localize, enhance and segment the mitral valve autonomously in 182 non-selected clinical cardiac ultrasound sequences. Correct autonomous localization by the algorithm was feasible in 165 of 182 reconstructed ultrasound sequences, using the experienced echocardiographer as reference. This corresponds to a 91% accuracy of the proposed method in unselected clinical data. Thus, multidimensional multiscale wavelet footprints allow successful autonomous detection and segmentation of the mitral valve with good accuracy in dynamic cardiac ultrasound sequences which are otherwise difficult to analyse due to their high noise level.
Auditory motion affects visual biological motion processing.
Brooks, A; van der Zwan, R; Billard, A; Petreska, B; Clarke, S; Blanke, O
2007-02-01
The processing of biological motion is a critical, everyday task performed with remarkable efficiency by human sensory systems. Interest in this ability has focused to a large extent on biological motion processing in the visual modality (see, for example, Cutting, J. E., Moore, C., & Morrison, R. (1988). Masking the motions of human gait. Perception and Psychophysics, 44(4), 339-347). In naturalistic settings, however, it is often the case that biological motion is defined by input to more than one sensory modality. For this reason, here in a series of experiments we investigate behavioural correlates of multisensory, in particular audiovisual, integration in the processing of biological motion cues. More specifically, using a new psychophysical paradigm we investigate the effect of suprathreshold auditory motion on perceptions of visually defined biological motion. Unlike data from previous studies investigating audiovisual integration in linear motion processing [Meyer, G. F. & Wuerger, S. M. (2001). Cross-modal integration of auditory and visual motion signals. Neuroreport, 12(11), 2557-2560; Wuerger, S. M., Hofbauer, M., & Meyer, G. F. (2003). The integration of auditory and motion signals at threshold. Perception and Psychophysics, 65(8), 1188-1196; Alais, D. & Burr, D. (2004). No direction-specific bimodal facilitation for audiovisual motion detection. Cognitive Brain Research, 19, 185-194], we report the existence of direction-selective effects: relative to control (stationary) auditory conditions, auditory motion in the same direction as the visually defined biological motion target increased its detectability, whereas auditory motion in the opposite direction had the inverse effect. Our data suggest these effects do not arise through general shifts in visuo-spatial attention, but instead are a consequence of motion-sensitive, direction-tuned integration mechanisms that are, if not unique to biological visual motion, at least not common to all types of
Analysis of cardiac interventricular septum motion in different respiratory states
NASA Astrophysics Data System (ADS)
Tautz, Lennart; Feng, Li; Otazo, Ricardo; Hennemuth, Anja; Axel, Leon
2016-03-01
The interaction between the left and right heart ventricles (LV and RV) depends on load and pressure conditions that are affected by cardiac contraction and respiration cycles. A novel MRI sequence, XD-GRASP, allows the acquisition of multi-dimensional, respiration-sorted and cardiac-synchronized free-breathing image data. In these data, effects of the cardiac and respiratory cycles on the LV/RV interaction can be observed independently. To enable the analysis of such data, we developed a semi-automatic exploration workflow. After tracking a cross-sectional line positioned over the heart, over all motion states, the septum and heart wall border locations are detected by analyzing the grey-value profile under the lines. These data are used to quantify septum motion, both in absolute units and as a fraction of the heart size, to compare values for different subjects. In addition to conventional visualization techniques, we used color maps for intuitive exploration of the variable values for this multi-dimensional data set. We acquired short-axis image data of nine healthy volunteers, to analyze the position and the motion of the interventricular septum in different breathing states and different cardiac cycle phases. The results indicate a consistent range of normal septum motion values, and also suggest that respiratory phase-dependent septum motion is greatest near end-diastolic phases. These new methods are a promising tool to assess LV/RV ventricle interaction and the effects of respiration on this interaction.
Airborne multidimensional integrated remote sensing system
NASA Astrophysics Data System (ADS)
Xu, Weiming; Wang, Jianyu; Shu, Rong; He, Zhiping; Ma, Yanhua
2006-12-01
In this paper, we present a kind of airborne multidimensional integrated remote sensing system that consists of an imaging spectrometer, a three-line scanner, a laser ranger, a position & orientation subsystem and a stabilizer PAV30. The imaging spectrometer is composed of two sets of identical push-broom high spectral imager with a field of view of 22°, which provides a field of view of 42°. The spectral range of the imaging spectrometer is from 420nm to 900nm, and its spectral resolution is 5nm. The three-line scanner is composed of two pieces of panchromatic CCD and a RGB CCD with 20° stereo angle and 10cm GSD(Ground Sample Distance) with 1000m flying height. The laser ranger can provide height data of three points every other four scanning lines of the spectral imager and those three points are calibrated to match the corresponding pixels of the spectral imager. The post-processing attitude accuracy of POS/AV 510 used as the position & orientation subsystem, which is the aerial special exterior parameters measuring product of Canadian Applanix Corporation, is 0.005° combined with base station data. The airborne multidimensional integrated remote sensing system was implemented successfully, performed the first flying experiment on April, 2005, and obtained satisfying data.
Multidimensional stress management in nursing education.
Russler, M F
1991-10-01
This study investigated the effectiveness of multidimensional stress management training for beginning baccalaureate nursing students (N = 57). An experimental pretest-posttest placebo group, control group design was used. Two pretest and three posttest measurements of the dependent variables of state anxiety (SA), reported emotions, and coping methods were completed. The program incorporated cognitive, physiological, and behavioral approaches. Second, this study examined the relationship of self-esteem, recent life experiences, and trait anxiety (TA) to encountered stressors. A repeated measures analysis of variance demonstrated no significant differences between treatment groups across time. However, written workshop evaluations demonstrated a strongly positive response by the experimental group. Significant within-subjects change was demonstrated for all 57 subjects over the semester on the dependent variables of SA, Threat emotions, and Challenge emotions reinforcing Lazarus' transactional model. A correlation matrix revealed that individuals with low self-esteem appraised the environment in a negative manner as did those subjects with high state and TA. Recommendations include further revision of the multidimensional stress management approach and continued use of the transactional theoretical framework. PMID:1658267
Multidimensional smooth loops with universal elasticity
NASA Astrophysics Data System (ADS)
Dzhukashev, K. R.; Shelekhov, A. M.
2015-05-01
Let \\widetilde E be a universal (isotopically invariant) identity that is derived from the elasticity identity E\\colon (xy)x=x(yx). One of the authors has previously shown that a) each local loop of dimension r with identity \\widetilde E (briefly, a loop \\widetilde E) is a smooth middle Bol loop of dimension r; b) smooth two-dimensional loops \\widetilde E are Lie groups; c) up to isotopy, there exist only two three-dimensional loops \\widetilde E: the loops E_1 and E_2. In this paper, the loops E_1 and E_2 are extended to the multidimensional case. The fact that each smooth loop \\widetilde E of dimension r corresponds to a unique multidimensional three-web on a manifold of dimension 2r is key to our work. In addition, the class of loops under investigation is characterized by the fact that the torsion tensor of the corresponding web has rank 1 (that is, the algebra generated by this tensor has a one-dimensional derived algebra). This enables us to express the differential equations of the problem in an invariant form. The system of equations thus obtained was found to be amenable to integration in the most general case, and the equations of the required loops have been obtained in local coordinates. Bibliography: 17 titles.
MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS
Fang, X.; Xia, C.; Keppens, R.
2013-07-10
We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.
Multidimensional Modeling of Coronal Rain Dynamics
NASA Astrophysics Data System (ADS)
Fang, X.; Xia, C.; Keppens, R.
2013-07-01
We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.
Multidimensional gravity in the nonrelativistic limit
NASA Astrophysics Data System (ADS)
Eingorn, Maxim; Zhuk, Alexander
2009-12-01
Exact solutions of the Poisson equation are found for multidimensional spaces with topology M3+d=R3×Td. These solutions describe smooth transitions from Newtonian behavior 1/r3 for distances bigger than the periods of the tori (the sizes of the extra dimensions) to multidimensional behavior 1/r3+d1+d in the small-distance limit. In the case of one extra dimension d=1, a compact and elegant formula for the gravitational potential is found. It is shown that corrections to the gravitational constant in Cavendish-type experiments can be within the measurement accuracy of Newton’s gravitational constant GN. Models with test masses smeared over some (or all) extra dimensions are proposed. It is shown that in a 10-dimensional spacetime with three smeared extra dimensions the size of the remaining three extra dimensions can be enlarged up to submillimeter scales in case of a fundamental Planck scale MPl(10)≈1TeV. In models with all extra dimensions smeared, the gravitational potential coincides exactly with the Newtonian one. Nevertheless, the hierarchy problem can be solved in these models.
Multidimensional Conservation Laws and Low Regularity Solutions
Barbara Lee Keyfitz
2007-06-16
This is the concluding report for the project, a continuation of research by Keyfitz and co-workers on multidimensional conservation laws, and applications of nonhyperbolic conservation laws in the two-fluid model for multiphase flow. The multidimensional research project was started with Suncica Canic, at the University of Houston and with Eun Heui Kim, now at California State University Long Beach. Two postdoctoral researchers, Katarina Jegdic and Allen Tesdall, also worked on this research. Jegdic's research was supported (for a total of one year) by this grant. Work on nonhyperbolic models for two-phase flows is being pursued jointly with Michael Sever, Hebrew University. Background for the project is contained in earlier reports. Note that in 2006, the project received a one-year no-cost extension that will end in September, 2007. A new proposal, for continuation of the research and for new projects, will be submitted in the Fall of 2007, with funding requested to begin in the summer of 2008. The reason for the 'funding gap' is Keyfitz's four-year stint as Director of the Fields Institute in Toronto, Canada. The research has continued, but has been supported by Canadian grant funds, as seems appropriate during this period.
Limited range of motion is a term meaning that a joint or body part cannot move through its normal range of motion. ... Motion may be limited because of a problem within the joint, swelling of tissue around the joint, ...
Self Motion Perception and Motion Sickness
NASA Technical Reports Server (NTRS)
Fox, Robert A. (Principal Investigator)
1991-01-01
The studies conducted in this research project examined several aspects of motion sickness in animal models. A principle objective of these studies was to investigate the neuroanatomy that is important in motion sickness with the objectives of examining both the utility of putative models and defining neural mechanisms that are important in motion sickness.
Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology
ERIC Educational Resources Information Center
Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei
2015-01-01
This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…
Entropic uncertainty relations in multidimensional position and momentum spaces
Huang Yichen
2011-05-15
Commutator-based entropic uncertainty relations in multidimensional position and momentum spaces are derived, twofold generalizing previous entropic uncertainty relations for one-mode states. They provide optimal lower bounds and imply the multidimensional variance-based uncertainty principle. The article concludes with an open conjecture.
Multidimensional Physical Self-Concept of Athletes with Physical Disabilities
ERIC Educational Resources Information Center
Shapiro, Deborah R.; Martin, Jeffrey J.
2010-01-01
The purposes of this investigation were first to predict reported PA (physical activity) behavior and self-esteem using a multidimensional physical self-concept model and second to describe perceptions of multidimensional physical self-concept (e.g., strength, endurance, sport competence) among athletes with physical disabilities. Athletes (N =…
The Tunneling Method for Global Optimization in Multidimensional Scaling.
ERIC Educational Resources Information Center
Groenen, Patrick J. F.; Heiser, Willem J.
1996-01-01
A tunneling method for global minimization in multidimensional scaling is introduced and adjusted for multidimensional scaling with general Minkowski distances. The method alternates a local search step with a tunneling step in which a different configuration is sought with the same STRESS implementation. (SLD)
Heteronuclear Multidimensional Protein NMR in a Teaching Laboratory
ERIC Educational Resources Information Center
Wright, Nathan T.
2016-01-01
Heteronuclear multidimensional NMR techniques are commonly used to study protein structure, function, and dynamics, yet they are rarely taught at the undergraduate level. Here, we describe a senior undergraduate laboratory where students collect, process, and analyze heteronuclear multidimensional NMR experiments using an unstudied Ig domain (Ig2…
Multidimensional hydrodynamic convection in full amplitude RR Lyrae models
NASA Astrophysics Data System (ADS)
Deupree, R.; Geroux, C.
2016-05-01
Multidimensional (both 2D and 3D) hydrodynamic calculations have been performed to compute full amplitude RR Lyrae models. The multi- dimensional nature allows convection to be treated in a more realistic way than simple 1D formulations such as the local mixing length theory. We focus on some aspects of multidimensional calculations and on the model for treating convection.
Evaluating Item Fit for Multidimensional Item Response Models
ERIC Educational Resources Information Center
Zhang, Bo; Stone, Clement A.
2008-01-01
This research examines the utility of the s-x[superscript 2] statistic proposed by Orlando and Thissen (2000) in evaluating item fit for multidimensional item response models. Monte Carlo simulation was conducted to investigate both the Type I error and statistical power of this fit statistic in analyzing two kinds of multidimensional test…
The Concept of Aptitude and Multidimensional Validity Revisited.
ERIC Educational Resources Information Center
Roeser, Robert W.; Shavelson, Richard J.; Kupermintz, Haggai; Lau, Shun; Ayala, Carlos; Haydel, Angela; Schultz, Susan; Gallagher, Larry; Quihuis, Gisell
2002-01-01
Provides an overview of the approach of Richard E. Snow to the concept of aptitude and multidimensional validity and summarizes the studies in this special issue. Overall, studies confirmed the multidimensional structure of science achievement scores, the validity of some key motivational constructs for predicting achievement, and other ideas…
Self-Motion Perception and Motion Sickness
NASA Technical Reports Server (NTRS)
Fox, Robert A.
1991-01-01
Motion sickness typically is considered a bothersome artifact of exposure to passive motion in vehicles of conveyance. This condition seldom has significant impact on the health of individuals because it is of brief duration, it usually can be prevented by simply avoiding the eliciting condition and, when the conditions that produce it are unavoidable, sickness dissipates with continued exposure. The studies conducted examined several aspects of motion sickness in animal models. A principle objective of these studies was to investigate the neuroanatomy that is important in motion sickness with the objectives of examining both the utility of putative models and defining neural mechanisms that are important in motion sickness.
Multidimensional multiphysics simulation of TRISO particle fuel
NASA Astrophysics Data System (ADS)
Hales, J. D.; Williamson, R. L.; Novascone, S. R.; Perez, D. M.; Spencer, B. W.; Pastore, G.
2013-11-01
Multidimensional multiphysics analysis of TRISO-coated particle fuel using the BISON finite element nuclear fuels code is described. The governing equations and material models applicable to particle fuel and implemented in BISON are outlined. Code verification based on a recent IAEA benchmarking exercise is described, and excellent comparisons are reported. Multiple TRISO-coated particles of increasing geometric complexity are considered. The code's ability to use the same algorithms and models to solve problems of varying dimensionality from 1D through 3D is demonstrated. The code provides rapid solutions of 1D spherically symmetric and 2D axially symmetric models, and its scalable parallel processing capability allows for solutions of large, complex 3D models. Additionally, the flexibility to easily include new physical and material models and straightforward ability to couple to lower length scale simulations makes BISON a powerful tool for simulation of coated-particle fuel. Future code development activities and potential applications are identified.
Multidimensional Multiphysics Simulation of TRISO Particle Fuel
J. D. Hales; R. L. Williamson; S. R. Novascone; D. M. Perez; B. W. Spencer; G. Pastore
2013-11-01
Multidimensional multiphysics analysis of TRISO-coated particle fuel using the BISON finite-element based nuclear fuels code is described. The governing equations and material models applicable to particle fuel and implemented in BISON are outlined. Code verification based on a recent IAEA benchmarking exercise is described, and excellant comparisons are reported. Multiple TRISO-coated particles of increasing geometric complexity are considered. It is shown that the code's ability to perform large-scale parallel computations permits application to complex 3D phenomena while very efficient solutions for either 1D spherically symmetric or 2D axisymmetric geometries are straightforward. Additionally, the flexibility to easily include new physical and material models and uncomplicated ability to couple to lower length scale simulations makes BISON a powerful tool for simulation of coated-particle fuel. Future code development activities and potential applications are identified.
Multidimensional student skills with collaborative filtering
NASA Astrophysics Data System (ADS)
Bergner, Yoav; Rayyan, Saif; Seaton, Daniel; Pritchard, David E.
2013-01-01
Despite the fact that a physics course typically culminates in one final grade for the student, many instructors and researchers believe that there are multiple skills that students acquire to achieve mastery. Assessment validation and data analysis in general may thus benefit from extension to multidimensional ability. This paper introduces an approach for model determination and dimensionality analysis using collaborative filtering (CF), which is related to factor analysis and item response theory (IRT). Model selection is guided by machine learning perspectives, seeking to maximize the accuracy in predicting which students will answer which items correctly. We apply the CF to response data for the Mechanics Baseline Test and combine the results with prior analysis using unidimensional IRT.
Multidimensional scaling of musical time estimations.
Cocenas-Silva, Raquel; Bueno, José Lino Oliveira; Molin, Paul; Bigand, Emmanuel
2011-06-01
The aim of this study was to identify the psycho-musical factors that govern time evaluation in Western music from baroque, classic, romantic, and modern repertoires. The excerpts were previously found to represent variability in musical properties and to induce four main categories of emotions. 48 participants (musicians and nonmusicians) freely listened to 16 musical excerpts (lasting 20 sec. each) and grouped those that seemed to have the same duration. Then, participants associated each group of excerpts to one of a set of sine wave tones varying in duration from 16 to 24 sec. Multidimensional scaling analysis generated a two-dimensional solution for these time judgments. Musical excerpts with high arousal produced an overestimation of time, and affective valence had little influence on time perception. The duration was also overestimated when tempo and loudness were higher, and to a lesser extent, timbre density. In contrast, musical tension had little influence. PMID:21853763
Lesbian coming out as a multidimensional process.
Morris, J F
1997-01-01
Coming out for lesbians is discussed as a multidimensional process. Four dimensions are presented and explored. First is sexual identity formation which encompasses development of lesbian sexuality and awareness of being a lesbian. Second is disclosure of sexual orientation to others. Third is sexual expression and behavior. Fourth is lesbian consciousness which refers to how lesbians see themselves in relation to the social environment, including lesbian and gay communities. These dimensions are examined in relation to existing theories and research about lesbian coming out processes. Further, there is a discussion of coming out and demographic differences among lesbians. The possible impact of age, race, ethnicity, religion, geographic location, income, employment, and education on lesbian coming out are considered. PMID:9210010
Biological evolution in a multidimensional fitness landscape.
Saakian, David B; Kirakosyan, Zara; Hu, Chin-Kun
2012-09-01
We considered a multiblock molecular model of biological evolution, in which fitness is a function of the mean types of alleles located at different parts (blocks) of the genome. We formulated an infinite population model with selection and mutation, and calculated the mean fitness. For the case of recombination, we formulated a model with a multidimensional fitness landscape (the dimension of the space is equal to the number of blocks) and derived a theorem about the dynamics of initially narrow distribution. We also considered the case of lethal mutations. We also formulated the finite population version of the model in the case of lethal mutations. Our models, derived for the virus evolution, are interesting also for the statistical mechanics and the Hamilton-Jacobi equation as well. PMID:23030957
AMADA-Analysis of multidimensional astronomical datasets
NASA Astrophysics Data System (ADS)
de Souza, R. S.; Ciardi, B.
2015-09-01
We present AMADA, an interactive web application to analyze multidimensional datasets. The user uploads a simple ASCII file and AMADA performs a number of exploratory analysis together with contemporary visualizations diagnostics. The package performs a hierarchical clustering in the parameter space, and the user can choose among linear, monotonic or non-linear correlation analysis. AMADA provides a number of clustering visualization diagnostics such as heatmaps, dendrograms, chord diagrams, and graphs. In addition, AMADA has the option to run a standard or robust principal components analysis, displaying the results as polar bar plots. The code is written in R and the web interface was created using the SHINY framework. AMADA source-code is freely available at https://goo.gl/KeSPue, and the shiny-app at http://goo.gl/UTnU7I.
Multidimensional Langevin Modeling of Nonoverdamped Dynamics
NASA Astrophysics Data System (ADS)
Schaudinnus, Norbert; Bastian, Björn; Hegger, Rainer; Stock, Gerhard
2015-07-01
Based on a given time series, data-driven Langevin modeling aims to construct a low-dimensional dynamical model of the underlying system. When dealing with physical data as provided by, e.g., all-atom molecular dynamics simulations, effects due to small damping may be important to correctly describe the statistics (e.g., the energy landscape) and the dynamics (e.g., transition times). To include these effects in a dynamical model, an algorithm that propagates a second-order Langevin scheme is derived, which facilitates the treatment of multidimensional data. Adopting extensive molecular dynamics simulations of a peptide helix, a five-dimensional model is constructed that successfully forecasts the complex structural dynamics of the system. Neglect of small damping effects, on the other hand, is shown to lead to significant errors and inconsistencies.
Multidimensional Scaling Visualization Using Parametric Entropy
NASA Astrophysics Data System (ADS)
Lopes, António M.; Tenreiro Machado, J. A.; Galhano, Alexandra M.
2015-12-01
This paper studies complex systems using a generalized multidimensional scaling (MDS) technique. Complex systems are characterized by time-series responses, interpreted as a manifestation of their dynamics. Two types of time-series are analyzed, namely 18 stock markets and the gross domestic product per capita of 18 countries. For constructing the MDS charts, indices based on parametric entropies are adopted. Multiparameter entropies allow the variation of the parameters leading to alternative sets of charts. The final MDS maps are then assembled by means of Procrustes’ method that maximizes the fit between the individual charts. Therefore, the proposed method can be interpreted as a generalization to higher dimensions of the standard technique that represents (and discretizes) items by means of single “points” (i.e. zero-dimensional “objects”). The MDS plots, involving one-, two- and three-dimensional “objects”, reveal a good performance in capturing the correlations between data.
Multi-dimensional Indoor Location Information Model
NASA Astrophysics Data System (ADS)
Xiong, Q.; Zhu, Q.; Zlatanova, S.; Huang, L.; Zhou, Y.; Du, Z.
2013-11-01
Aiming at the increasing requirements of seamless indoor and outdoor navigation and location service, a Chinese standard of Multidimensional Indoor Location Information Model is being developed, which defines ontology of indoor location. The model is complementary to 3D concepts like CityGML and IndoorGML. The goal of the model is to provide an exchange GML-based format for location needed for indoor routing and navigation. An elaborated user requirements analysis and investigation of state-of-the-art technology in expressing indoor location at home and abroad was completed to identify the manner humans specify location. The ultimate goal is to provide an ontology that will allow absolute and relative specification of location such as "in room 321", "on the second floor", as well as, "two meters from the second window", "12 steps from the door".
Masking failures of multidimensional sensors (extended abstract)
NASA Technical Reports Server (NTRS)
Chew, Paul; Marzullo, Keith
1990-01-01
When a computer monitors a physical process, the computer uses sensors to determine the values of the physical variables that represent the state of the process. A sensor can sometimes fail, however, and in the worst case report a value completely unrelated to the true physical value. The work described is motivated by a methodology for transforming a process control program that can not tolerate sensor failure into one that can. In this methodology, a reliable abstract sensor is created by combining information from several real sensors that measure the same physical value. To be useful, an abstract sensor must deliver reasonably accurate information at reasonable computational cost. Sensors are considered that deliver multidimensional values (e.g., location or velocity in three dimensions, or both temperature and pressure). Geometric techniques are used to derive upper bounds on abstract sensor accuracy and to develop efficient algorithms for implementing abstract sensors.
Path integral learning of multidimensional movement trajectories
NASA Astrophysics Data System (ADS)
André, João; Santos, Cristina; Costa, Lino
2013-10-01
This paper explores the use of Path Integral Methods, particularly several variants of the recent Path Integral Policy Improvement (PI2) algorithm in multidimensional movement parametrized policy learning. We rely on Dynamic Movement Primitives (DMPs) to codify discrete and rhythmic trajectories, and apply the PI2-CMA and PIBB methods in the learning of optimal policy parameters, according to different cost functions that inherently encode movement objectives. Additionally we merge both of these variants and propose the PIBB-CMA algorithm, comparing all of them with the vanilla version of PI2. From the obtained results we conclude that PIBB-CMA surpasses all other methods in terms of convergence speed and iterative final cost, which leads to an increased interest in its application to more complex robotic problems.
A study of multidimensional modeling approaches for data warehouse
NASA Astrophysics Data System (ADS)
Yusof, Sharmila Mat; Sidi, Fatimah; Ibrahim, Hamidah; Affendey, Lilly Suriani
2016-08-01
Data warehouse system is used to support the process of organizational decision making. Hence, the system must extract and integrate information from heterogeneous data sources in order to uncover relevant knowledge suitable for decision making process. However, the development of data warehouse is a difficult and complex process especially in its conceptual design (multidimensional modeling). Thus, there have been various approaches proposed to overcome the difficulty. This study surveys and compares the approaches of multidimensional modeling and highlights the issues, trend and solution proposed to date. The contribution is on the state of the art of the multidimensional modeling design.
NASA Astrophysics Data System (ADS)
Bodin, Jacques
2015-03-01
In this study, new multi-dimensional time-domain random walk (TDRW) algorithms are derived from approximate one-dimensional (1-D), two-dimensional (2-D), and three-dimensional (3-D) analytical solutions of the advection-dispersion equation and from exact 1-D, 2-D, and 3-D analytical solutions of the pure-diffusion equation. These algorithms enable the calculation of both the time required for a particle to travel a specified distance in a homogeneous medium and the mass recovery at the observation point, which may be incomplete due to 2-D or 3-D transverse dispersion or diffusion. The method is extended to heterogeneous media, represented as a piecewise collection of homogeneous media. The particle motion is then decomposed along a series of intermediate checkpoints located on the medium interface boundaries. The accuracy of the multi-dimensional TDRW method is verified against (i) exact analytical solutions of solute transport in homogeneous media and (ii) finite-difference simulations in a synthetic 2-D heterogeneous medium of simple geometry. The results demonstrate that the method is ideally suited to purely diffusive transport and to advection-dispersion transport problems dominated by advection. Conversely, the method is not recommended for highly dispersive transport problems because the accuracy of the advection-dispersion TDRW algorithms degrades rapidly for a low Péclet number, consistent with the accuracy limit of the approximate analytical solutions. The proposed approach provides a unified methodology for deriving multi-dimensional time-domain particle equations and may be applicable to other mathematical transport models, provided that appropriate analytical solutions are available.
NASA Multidimensional Stirling Convertor Code Developed
NASA Technical Reports Server (NTRS)
Tew, Roy C.; Thieme, Lanny G.
2004-01-01
A high-efficiency Stirling Radioisotope Generator (SRG) for use on potential NASA Space Science missions is being developed by the Department of Energy, Lockheed Martin, Stirling Technology Company, and the NASA Glenn Research Center. These missions may include providing spacecraft onboard electric power for deep space missions or power for unmanned Mars rovers. Glenn is also developing advanced technology for Stirling convertors, aimed at substantially improving the specific power and efficiency of the convertor and the overall power system. Performance and mass improvement goals have been established for second- and third-generation Stirling radioisotope power systems. Multiple efforts are underway to achieve these goals, both in house at Glenn and under various grants and contracts. These efforts include the development of a multidimensional Stirling computational fluid dynamics code, high-temperature materials, advanced controllers, an end-to-end system dynamics model, low-vibration techniques, advanced regenerators, and a lightweight convertor. Under a NASA grant, Cleveland State University (CSU) and its subcontractors, the University of Minnesota (UMN) and Gedeon Associates, have developed a twodimensional computer simulation of a CSUmod Stirling convertor. The CFD-ACE commercial software developed by CFD Research Corp. of Huntsville, Alabama, is being used. The CSUmod is a scaled version of the Stirling Technology Demonstrator Convertor (TDC), which was designed and fabricated by the Stirling Technology Company and is being tested by NASA. The schematic illustrates the structure of this model. Modeled are the fluid-flow and heat-transfer phenomena that occur in the expansion space, the heater, the regenerator, the cooler, the compression space, the surrounding walls, and the moving piston and displacer. In addition, the overall heat transfer, the indicated power, and the efficiency can be calculated. The CSUmod model is being converted to a two
Multi-dimensional tunnelling and complex momentum
NASA Technical Reports Server (NTRS)
Bowcock, Peter; Gregory, Ruth
1991-01-01
The problem of modeling tunneling phenomena in more than one dimension is examined. It is found that existing techniques are inadequate in a wide class of situations, due to their inability to deal with concurrent classical motion. The generalization of these methods to allow for complex momenta is shown, and improved techniques are demonstrated with a selection of illustrative examples. Possible applications are presented.
The space transformation in the simulation of multidimensional random fields
Christakos, G.
1987-01-01
Space transformations are proposed as a mathematically meaningful and practically comprehensive approach to simulate multidimensional random fields. Within this context the turning bands method of simulation is reconsidered and improved in both the space and frequency domains. ?? 1987.
A multidimensional subdiffusion model: An arbitrage-free market
NASA Astrophysics Data System (ADS)
Li, Guo-Hua; Zhang, Hong; Luo, Mao-Kang
2012-12-01
To capture the subdiffusive characteristics of financial markets, the subordinated process, directed by the inverse α-stale subordinator Sα(t) for 0 < α < 1, has been employed as the model of asset prices. In this article, we introduce a multidimensional subdiffusion model that has a bond and K correlated stocks. The stock price process is a multidimensional subdiffusion process directed by the inverse α-stable subordinator. This model describes the period of stagnation for each stock and the behavior of the dependency between multiple stocks. Moreover, we derive the multidimensional fractional backward Kolmogorov equation for the subordinated process using the Laplace transform technique. Finally, using a martingale approach, we prove that the multidimensional subdiffusion model is arbitrage-free, and also gives an arbitrage-free pricing rule for contingent claims associated with the martingale measure.
Design of Multidimensional Shinnar-Le Roux RF Pulses
Ma, Chao; Liang, Zhi-Pei
2014-01-01
Purpose To generalize the conventional Shinnar-Le Roux (SLR) method for the design of multidimensional RF pulses. Methods Using echo-planar gradients, the multidimensional RF pulse design problem was converted into a series of 1D polynomial design problems. Each of the 1D polynomial design problems was solved efficiently. B0 inhomogeneity compensation and design of spatial-spectral pulses were also considered. Results The proposed method was used to design 2D excitation and refocusing pulses. The results were validated through Bloch equation simulation and experiments on a 3.0 T scanner. Large-tip-angle, equiripple-error, multidimensional excitation was achieved with ripple levels closely matching the design specifications. Conclusion The conventional SLR method can be extended to design multidimensional RF pulses. The proposed method achieves almost equiripple excitation errors, allows easy control of the tradeoff among design parameters, and is computationally efficient. PMID:24578212
The Measurement of Self-Rated Depression: A Multidimensional Approach.
ERIC Educational Resources Information Center
Bolon, Kevin; Barling, Julian
1980-01-01
Investigates the capacity of the Zung Self-Rating Depression Scale for providing specific multidimensional descriptors of depressive behavior. Ideational, physiological and behavioral depression factors were evident in data from 96 normal, white university student volunteers. (Author/RH)
Exploring multidimensional free energy surfaces of peptides
NASA Astrophysics Data System (ADS)
Wang, Yan; Kuczera, Krzysztof
1997-03-01
A new statistical mechanics thermodynamic integration method is presented, enabling exploration of multidimensional conformational free energy surfaces of large flexible molecules. In this approach a single molecular dynamics simulation in which a set of coordinates has been constrained to fixed values yields the free energy gradient with respect to all coordinates in the set. The availability of the multidimensional gradient opens new possibilities for exploration of molecular conformational free energy surfaces, including free energy optimization to locate free energy minima, calculation of higher free energy derivatives, and finding optimal free energy paths between states. Additionally, choosing of all "soft" degrees of freedom as the constrained set leads to accelerated convergence of averages, effectively overcoming the sampling problem of free energy simulations. Two applications of the method are presented: Helical states of model peptides. For model peptides (Ala)n and (Aib)n where n=6,8,10 and Aib is α-methylalanine in vacuum, free energy maps and free energy optimization in φ-ψ space are used to locate free energy minima corresponding to α-, π- and 3_10-helical structures. The stability of the minima is characterized by calculating numerical second derivatives of the free energy. Free energy decomposition is employed to reveal the molecular mechanism for the improved stability of the 3_10h relative to the ah in Aib-containing peptides. DPDPE peptide pre-organization. For the linear form of the opioid peptide DPDPE in aqueous solution, the effective local sampling made possible by fixing all soft degrees of freedom is used to calculate the free energy difference between the open and cyclic-like structures, providing an estimate of the free energy of pre-organizing the peptide for disulfide bond formation. The open structure was found to be more stable by 4.0 ± 0.8 kcal/mol. The cyclic-like conformation was much better solvated than the open
Towards a genuinely multi-dimensional upwind scheme
NASA Technical Reports Server (NTRS)
Powell, Kenneth G.; Vanleer, Bram; Roe, Philip L.
1990-01-01
Methods of incorporating multi-dimensional ideas into algorithms for the solution of Euler equations are presented. Three schemes are developed and tested: a scheme based on a downwind distribution, a scheme based on a rotated Riemann solver and a scheme based on a generalized Riemann solver. The schemes show an improvement over first-order, grid-aligned upwind schemes, but the higher-order performance is less impressive. An outlook for the future of multi-dimensional upwind schemes is given.
Central Schemes for Multi-Dimensional Hamilton-Jacobi Equations
NASA Technical Reports Server (NTRS)
Bryson, Steve; Levy, Doron; Biegel, Bryan (Technical Monitor)
2002-01-01
We present new, efficient central schemes for multi-dimensional Hamilton-Jacobi equations. These non-oscillatory, non-staggered schemes are first- and second-order accurate and are designed to scale well with an increasing dimension. Efficiency is obtained by carefully choosing the location of the evolution points and by using a one-dimensional projection step. First-and second-order accuracy is verified for a variety of multi-dimensional, convex and non-convex problems.
Multidimensional Programming Methods for Energy Facility Siting: Alternative Approaches
NASA Technical Reports Server (NTRS)
Solomon, B. D.; Haynes, K. E.
1982-01-01
The use of multidimensional optimization methods in solving power plant siting problems, which are characterized by several conflicting, noncommensurable objectives is addressed. After a discussion of data requirements and exclusionary site screening methods for bounding the decision space, classes of multiobjective and goal programming models are discussed in the context of finite site selection. Advantages and limitations of these approaches are highlighted and the linkage of multidimensional methods with the subjective, behavioral components of the power plant siting process is emphasized.
Clustering multidimensional MR images to detect metabolic changes in different tissue classes
NASA Astrophysics Data System (ADS)
Bernarding, Johannes; Braun, Juergen; Villringer, Kersten; Haarbeck, Klaus; Hoehn-Berlage, Mathias; Haupt, G.; Wolf, Karl J.; Tolxdorff, Thomas
1996-04-01
A tissue database was established by using multidimensional clusters of exact longitudinal (T1) and transversal (T2) relaxation times and spin density, allowing the automatic segmentation and characterization of healthy and pathologic tissue. All parameters were simultaneously acquired employing a modified Multi-Echo pulse sequence. Initial clinical results showed a good differentiation between normal brain tissue and pathologic tissue like edema and meningioma. Inhomogeneous tumors such as high-grade glioblastoma were difficult to characterize automatically. The implementation of a diffusion-weighted modified Tanner-Stejskal pulse sequence allows the acquisition of the Apparent Diffusion Constant (ADC), which has been incorporated for the first time into a multidimensional information set as a new tissue-characterizing parameter. This parameter is sensitive to changes in the mobility of water in and between different cell compartments resulting from metabolic cell disorders like ischemic or edematous processes. To reproduce the known results of animal experiments, where as early as 30 min after an ischemic event the measurement of the ADC led to a diagnosis, diffusion-weighted imaging had to be implemented on a standard clinical scanner. The correction of unavoidable motion artifacts, which occur when applying diffusion- weighted spin echo sequences on standard clinical scanners, require the implementation of a special sequence using the navigator echo method followed by a correction algorithm of the raw data in Fourier space. Initial results showed a significant improvement in the differentiation of healthy and pathologic tissue classes.
Static imaging of motion: motion texture
NASA Astrophysics Data System (ADS)
Arimura, Koichi
1992-05-01
This paper describes how motion segmentation can be achieved by analyzing of a single static image that is created from a series of picture frames. The key idea is motion imaging; in other words, motion is expressed in static images by integrating, frame after frame, the spatiotemporal fluctuations of the gradient gray level at each local area. This tends to create blurred or attached line images (images with lines that show the path of movement of an object through space) on moving objects. We call this 'motion texture'. We computed motion texture images based on the animation of a natural scene and on a number of computer synthesized animations containing groups of moving objects (random dots). Moreover, we applied two different texture analyses to the motion textured images for segmentation: a texture analysis based on the local homogeneity of gray level gradation in similarly textured regions and another based on the structural feature of gray level gradation in motion texture. Experiments showed that subjective visual impressions of segmentation were quite different for these animations. The texture segmentation described here successfully grouped moving objects coincident to subjective impressions. In our random dot animations, the density of the basic motion vectors extracted from each pair of successive frames was set at a constant to compensate for the dot grouping effect based on the vector density. The dot appearance period (lifetime) is varied across the animations. In a long lifetime random dot animation, region boundaries can be more clearly perceived than in a short one. The different impressions may be explained by analyzing the motion texture elements, but can not always be represented successfully using the motion vectors between two successive frames whose density is set at a constant between the animations with the different lifetime.
Multidimensional thermal-chemical cookoff modeling
Baer, M.R.; Gross, R.J.; Gartling, D.K.; Hobbs, M.L.
1994-08-01
Multidimensional thermal/chemical modeling is an essential step in the development of a predictive capability for cookoff of energetic materials in systems subjected to abnormal thermal environments. COYOTE II is a state-of-the-art two- and three-dimensional finite element code for the solution of heat conduction problems including surface-to-surface thermal radiation heat transfer and decomposition chemistry. Multistep finite rate chemistry is incorporated into COYOTE II using an operator-splitting methodology; rate equations are solved element-by-element with a modified matrix-free stiff solver, CHEMEQ. COYOTE II is purposely designed with a user-oriented input structure compatible with the database, the pre-processing mesh generation, and the post-processing tools for data visualization shared with other engineering analysis codes available at Sandia National Laboratories. As demonstrated in a companion paper, decomposition during cookoff in a confined or semi-confined system leads to significant mechanical behavior. Although mechanical effect are not presently considered in COYOTE II, the formalism for including mechanics in multidimensions is under development.
Multi-dimensional cosmology and GUP
Zeynali, K.; Motavalli, H.; Darabi, F. E-mail: f.darabi@azaruniv.edu
2012-12-01
We consider a multidimensional cosmological model with FRW type metric having 4-dimensional space-time and d-dimensional Ricci-flat internal space sectors with a higher dimensional cosmological constant. We study the classical cosmology in commutative and GUP cases and obtain the corresponding exact solutions for negative and positive cosmological constants. It is shown that for negative cosmological constant, the commutative and GUP cases result in finite size universes with smaller size and longer ages, and larger size and shorter age, respectively. For positive cosmological constant, the commutative and GUP cases result in infinite size universes having late time accelerating behavior in good agreement with current observations. The accelerating phase starts in the GUP case sooner than the commutative case. In both commutative and GUP cases, and for both negative and positive cosmological constants, the internal space is stabilized to the sub-Planck size, at least within the present age of the universe. Then, we study the quantum cosmology by deriving the Wheeler-DeWitt equation, and obtain the exact solutions in the commutative case and the perturbative solutions in GUP case, to first order in the GUP small parameter, for both negative and positive cosmological constants. It is shown that good correspondence exists between the classical and quantum solutions.
Multidimensional in vivo hazard assessment using zebrafish.
Truong, Lisa; Reif, David M; St Mary, Lindsey; Geier, Mitra C; Truong, Hao D; Tanguay, Robert L
2014-01-01
There are tens of thousands of man-made chemicals in the environment; the inherent safety of most of these chemicals is not known. Relevant biological platforms and new computational tools are needed to prioritize testing of chemicals with limited human health hazard information. We describe an experimental design for high-throughput characterization of multidimensional in vivo effects with the power to evaluate trends relating to commonly cited chemical predictors. We evaluated all 1060 unique U.S. EPA ToxCast phase 1 and 2 compounds using the embryonic zebrafish and found that 487 induced significant adverse biological responses. The utilization of 18 simultaneously measured endpoints means that the entire system serves as a robust biological sensor for chemical hazard. The experimental design enabled us to describe global patterns of variation across tested compounds, evaluate the concordance of the available in vitro and in vivo phase 1 data with this study, highlight specific mechanisms/value-added/novel biology related to notochord development, and demonstrate that the developmental zebrafish detects adverse responses that would be missed by less comprehensive testing strategies. PMID:24136191
Determination of Multidimensional Intermolecular Potential Energy Surfaces
NASA Astrophysics Data System (ADS)
Cohen, Ronald Carl
High resolution spectroscopy of the low frequency van der Waals vibrations (also referred to as Vibration -Rotation-Tunneling (VRT) spectroscopy) in weakly bound complexes provides the means to probe intermolecular forces with unprecedented detail and precision. We present an overview of the experimental information on intermolecular forces and intermolecular dynamics which has been obtained by far infrared VRT spectroscopy of 18 complexes. We then turn to a detailed examination of the Ar-H_2O complex, a simple prototype for the study of intermolecular forces. The measurement and analysis of 9 VRT bands is described. These data are first used to obtain a qualitative description of the intermolecular potential energy surface (IPS). A new simple and efficient method for calculating the eigenvalues of the multidimensional intermolecular dynamics on the IPS has been developed. This algorithm (an adaptation of the Collocation Method) was then used in a direct fit to obtain an accurate and detailed description of the intermolecular forces acting within the Ar-H_2O complex.
Multidimensional scaling visualization of earthquake phenomena
NASA Astrophysics Data System (ADS)
Lopes, António M.; Machado, J. A. Tenreiro; Pinto, C. M. A.; Galhano, A. M. S. F.
2014-01-01
Earthquakes are associated with negative events, such as large number of casualties, destruction of buildings and infrastructures, or emergence of tsunamis. In this paper, we apply the Multidimensional Scaling (MDS) analysis to earthquake data. MDS is a set of techniques that produce spatial or geometric representations of complex objects, such that, objects perceived to be similar/distinct in some sense are placed nearby/distant on the MDS maps. The interpretation of the charts is based on the resulting clusters since MDS produces a different locus for each similarity measure. In this study, over three million seismic occurrences, covering the period from January 1, 1904 up to March 14, 2012 are analyzed. The events, characterized by their magnitude and spatiotemporal distributions, are divided into groups, either according to the Flinn-Engdahl seismic regions of Earth or using a rectangular grid based in latitude and longitude coordinates. Space-time and Space-frequency correlation indices are proposed to quantify the similarities among events. MDS has the advantage of avoiding sensitivity to the non-uniform spatial distribution of seismic data, resulting from poorly instrumented areas, and is well suited for accessing dynamics of complex systems. MDS maps are proven as an intuitive and useful visual representation of the complex relationships that are present among seismic events, which may not be perceived on traditional geographic maps. Therefore, MDS constitutes a valid alternative to classic visualization tools, for understanding the global behavior of earthquakes.
A Computational Model of Multidimensional Shape
Liu, Xiuwen; Shi, Yonggang; Dinov, Ivo
2010-01-01
We develop a computational model of shape that extends existing Riemannian models of curves to multidimensional objects of general topological type. We construct shape spaces equipped with geodesic metrics that measure how costly it is to interpolate two shapes through elastic deformations. The model employs a representation of shape based on the discrete exterior derivative of parametrizations over a finite simplicial complex. We develop algorithms to calculate geodesics and geodesic distances, as well as tools to quantify local shape similarities and contrasts, thus obtaining a formulation that accounts for regional differences and integrates them into a global measure of dissimilarity. The Riemannian shape spaces provide a common framework to treat numerous problems such as the statistical modeling of shapes, the comparison of shapes associated with different individuals or groups, and modeling and simulation of shape dynamics. We give multiple examples of geodesic interpolations and illustrations of the use of the models in brain mapping, particularly, the analysis of anatomical variation based on neuroimaging data. PMID:21057668
Multi-dimensionally encoded magnetic resonance imaging
Lin, Fa-Hsuan
2013-01-01
Magnetic resonance imaging typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here we propose the multi-dimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel RF coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. PMID:22926830
Multidimensional mass spectrometry-based shotgun lipidomics.
Wang, Miao; Han, Xianlin
2014-01-01
Multidimensional mass spectrometry-based shotgun lipidomics (MDMS-SL) has become a foundational analytical technology platform among current lipidomics practices due to its high efficiency, sensitivity, and reproducibility, as well as its broad coverage. This platform has been broadly used to determine the altered content and/or composition of lipid classes, subclasses, and individual molecular species induced by diseases, genetic manipulations, drug treatments, and aging, among others. Herein, we briefly discuss the principles underlying this technology and present a protocol for routine analysis of many of the lipid classes and subclasses covered by MDMS-SL directly from lipid extracts of biological samples. In particular, lipid sample preparation from a variety of biological materials, which is one of the key components of MDMS-SL, is described in detail. The protocol for mass spectrometric analysis can readily be expanded for analysis of other lipid classes not mentioned as long as appropriate sample preparation is conducted, and should aid researchers in the field to better understand and manage the technology for analysis of cellular lipidomes. PMID:25270931
Multidimensional work sampling in an outpatient pharmacy.
Murray, M D; Rupp, M T; Overhage, J M; Ebbeler, D E; Main, J W; Tierney, W M
1995-10-01
Multidimensional work sampling was performed at a hospital-based outpatient pharmacy. Data were collected from nine full-time and five part-time pharmacists over a 45-day baseline period. Pharmacists wore silent, random-signal generators that permitted continuous work sampling. We introduced the concept of quick codes to allow pharmacists to record their work using a single letter for repetitive activities. Pharmacists recorded 4,687 observations, 90 percent using quick codes. The most common activity was checking prescriptions (36.2 percent). Detection and correction of prescribing errors was the most common reason for their work (39.4 percent). Most work-related activities were performed alone (80 percent) with little time in contact with patients or physicians. These baseline measures will be compared with future measures to assess the effect of the implementation of computerized prospective drug utilization review and clinical treatment guidelines on pharmacists' work. It is expected that these technologic and process changes will increase opportunities for pharmacists to educate patients and consult with physicians. PMID:10151712
Correlative visualization techniques for multidimensional data
NASA Technical Reports Server (NTRS)
Treinish, Lloyd A.; Goettsche, Craig
1989-01-01
Critical to the understanding of data is the ability to provide pictorial or visual representation of those data, particularly in support of correlative data analysis. Despite the advancement of visualization techniques for scientific data over the last several years, there are still significant problems in bringing today's hardware and software technology into the hands of the typical scientist. For example, there are other computer science domains outside of computer graphics that are required to make visualization effective such as data management. Well-defined, flexible mechanisms for data access and management must be combined with rendering algorithms, data transformation, etc. to form a generic visualization pipeline. A generalized approach to data visualization is critical for the correlative analysis of distinct, complex, multidimensional data sets in the space and Earth sciences. Different classes of data representation techniques must be used within such a framework, which can range from simple, static two- and three-dimensional line plots to animation, surface rendering, and volumetric imaging. Static examples of actual data analyses will illustrate the importance of an effective pipeline in data visualization system.
Multidimensional indexing tools for the virtual observatory
NASA Astrophysics Data System (ADS)
Csabai, I.; Dobos, L.; Trencséni, M.; Herczegh, G.; Józsa, P.; Purger, N.; Budavári, T.; Szalay, A. S.
2007-10-01
The last decade has seen a dramatic change in the way astronomy is carried out. The dawn of the the new microelectronic devices, like CCDs has dramatically extended the amount of observed data. Large, in some cases all sky surveys emerged in almost all the wavelength ranges of the observable spectrum of electromagnetic waves. This large amount of data has to be organized, published electronically and a new style of data retrieval is essential to exploit all the hidden information in the multiwavelength data. Many statistical algorithms required for these tasks run reasonably fast when using small sets of in-memory data, but take noticeable performance hits when operating on large databases that do not fit into memory. We utilize new software technologies to develop and evaluate fast multidimensional indexing schemes that inherently follow the underlying, highly non-uniform distribution of the data: they are layered uniform indices, hierarchical binary space partitioning, and sampled flat Voronoi tessellation of the data. These techniques can dramatically speed up operations such as finding similar objects by example, classifying objects or comparing extensive simulation sets with observations.
Multidimensional time-correlated single photon counting
NASA Astrophysics Data System (ADS)
Becker, Wolfgang; Bergmann, Axel
2006-10-01
Time-correlated single photon counting (TCSPC) is based on the detection of single photons of a periodic light signal, measurement of the detection time of the photons, and the build-up of the photon distribution versus the time in the signal period. TCSPC achieves a near ideal counting efficiency and transit-time-spread-limited time resolution for a given detector. The drawback of traditional TCSPC is the low count rate, long acquisition time, and the fact that the technique is one-dimensional, i.e. limited to the recording of the pulse shape of light signals. We present an advanced TCSPC technique featuring multi-dimensional photon acquisition and a count rate close to the capability of currently available detectors. The technique is able to acquire photon distributions versus wavelength, spatial coordinates, and the time on the ps scale, and to record fast changes in the fluorescence lifetime and fluorescence intensity of a sample. Biomedical applications of advanced TCSPC techniques are time-domain optical tomography, recording of transient phenomena in biological systems, spectrally resolved fluorescence lifetime imaging, FRET experiments in living cells, and the investigation of dye-protein complexes by fluorescence correlation spectroscopy. We demonstrate the potential of the technique for selected applications.
Multidimensional In Vivo Hazard Assessment Using Zebrafish
Tanguay, Robert L.
2014-01-01
There are tens of thousands of man-made chemicals in the environment; the inherent safety of most of these chemicals is not known. Relevant biological platforms and new computational tools are needed to prioritize testing of chemicals with limited human health hazard information. We describe an experimental design for high-throughput characterization of multidimensional in vivo effects with the power to evaluate trends relating to commonly cited chemical predictors. We evaluated all 1060 unique U.S. EPA ToxCast phase 1 and 2 compounds using the embryonic zebrafish and found that 487 induced significant adverse biological responses. The utilization of 18 simultaneously measured endpoints means that the entire system serves as a robust biological sensor for chemical hazard. The experimental design enabled us to describe global patterns of variation across tested compounds, evaluate the concordance of the available in vitro and in vivo phase 1 data with this study, highlight specific mechanisms/value-added/novel biology related to notochord development, and demonstrate that the developmental zebrafish detects adverse responses that would be missed by less comprehensive testing strategies. PMID:24136191
A Multidimensional Study of Hadronization in Nuclei
NASA Astrophysics Data System (ADS)
Miles, Nathan; Deconinck, Wouter; Kordosky, Mike
2013-10-01
At the present moment there doest not exist a universal event generator in high energy neutrino physics and this is where GENIE (Generates Events for Neutrino Interaction Experiments) is currently being implemented. The aim for GENIE is to become and extensive canonical Monte Carlo (MC) event generator for a wide range of neutrino interactions and in order to achieve this GENIE must be repeatedly verified with experimental data collected from neutrino interaction experiments conducted around the world. This paper focuses on comparing data obtained in a multidimensional study of hadronization in nuclei done by the HERMES collaboration with a reproduction of a similar experiment via GENIE. The experiment was a simulation of colliding a beam of electron neutrinos at 27.6 GeV with carbon-12 and deuterium nuclei and then observing the dependence of hadron multiplicity ratios, RAh, of carbon to deuterium for ν, the energy transferred to the struck valence or sea quark by the virtual boson, and z, the fractional energy carried by the hadron produced as a result of exciting the valence or sea quark out of the nucleon. The dependence of the multiplicity ratios were analyzed for 8 different particles, π+, π-, π0, K+, K-, K0, p+, and p-. NSF grant and the College of William and Mary Physics Department.
Particle-Based Multidimensional Multispecies Biofilm Model
Picioreanu, Cristian; Kreft, Jan-Ulrich; van Loosdrecht, Mark C. M.
2004-01-01
In this paper we describe a spatially multidimensional (two-dimensional [2-D] and three-dimensional [3-D]) particle-based approach for modeling the dynamics of multispecies biofilms growing on multiple substrates. The model is based on diffusion-reaction mass balances for chemical species coupled with microbial growth and spreading of biomass represented by hard spherical particles. Effectively, this is a scaled-up version of a previously proposed individual-based biofilm model. Predictions of this new particle-based model were quantitatively compared with those obtained with an established one-dimensional (1-D) multispecies model for equivalent problems. A nitrifying biofilm containing aerobic ammonium and nitrite oxidizers, anaerobic ammonium oxidizers, and inert biomass was chosen as an example. The 2-D and 3-D models generally gave the same results. If only the average flux of nutrients needs to be known, 2-D and 1-D models are very similar. However, the behavior of intermediates, which are produced and consumed in different locations within the biofilm, is better described in 2-D and 3-D models because of the multidirectional concentration gradients. The predictions of 2-D or 3-D models are also different from those of 1-D models for slowly growing or minority species in the biofilm. This aspect is related to the mechanism of biomass spreading or advection implemented in the models and should receive more attention in future experimental studies. PMID:15128564
New methodology for multi-dimensional spinal joint testing with a parallel robot.
Walker, Matthew R; Dickey, James P
2007-03-01
Six degree-of-freedom (6DOF) robots can be used to examine joints and their mechanical properties with the spatial freedom encountered physiologically. Parallel robots are capable of 6DOF motion under large payloads making them ideal for joint testing. This study developed and assessed novel methods for spinal joint testing with a custom-built parallel robot implementing hybrid load-position control. We hypothesized these methods would allow multi-dimensional control of joint loading scenarios, resulting in physiological joint motions. Tests were performed in 3DOF and 6DOF. 3DOF methods controlled the forces and the principal moment within +/-10 N and 0.25 N m under combined bending and compressive loads. 6DOF tests required larger tolerances for convergence due to machine compliance, however expected motion patterns were still observed. The unique mechanism and control approaches show promise for enabling complex three-dimensional loading patterns for in vitro joint biomechanics, and could facilitate research using specimens with unknown, changing, or nonlinear load-deformation properties. PMID:17235615
ERIC Educational Resources Information Center
Tea, Peter L., Jr.
1988-01-01
Explains gyroscopic motions to college freshman or high school seniors who have learned about centripetal acceleration and the transformations of a couple. Contains several figures showing the direction of forces and motion. (YP)
Multidimensional analysis and probabilistic model of volcanic and seismic activities
NASA Astrophysics Data System (ADS)
Fedorov, V.
2009-04-01
. Features of spatial distribution of volcanic eruptions and earthquakes of magnitude 7 were analyzed, and those related to the Earth rotation identified. Frequencies of their spatial distribution are calculated. Using those parameters as the base, a scheme (algorithm) of probabilistic monitoring (long-range forecast) has been developed for volcanic and seismic events. Refereces (in Russian): 1. Fedorov V.M. Gravitational factors and astronomy-based chronology of processes in geospheres. Moscow University Publishing House, 2000. 368 p. 2. Fedorov V.M. Comparison between chronology of the Earth volcanic activity and characteristics of its orbital motion // Vulkanologiya i seismologiya, № 5, 2001, p. 65-67. 3. Fedorov V.M. Specific features of latitudinal distribution of volcanic eruptions// Vulkanologiya i seismologiya, № 4, 2002, p.39-43. 4. Fedorov V.M. Specific features of latitudinal distribution of endogenic relief-forming processes and the rotation of the Earth // Geomorphologiya, № 1, 2003, p.3-9. 5. Fedorov V.M. Comparison between chronology of the Earth volcanic and seismic activity and characteristics of its orbital motion // Izvestiya RAS. Ser. Geogr. № 5, 2003, p.16-20. 6. Fedorov V.M. Chronological structure and probability of volcanic events as related to tidal deformation of lithosphere // Vulkanologiya i seismologiya, № 1, 2005, p.44-50. 7. Fedorov V.M. Multidimensional analysis and a probabilistic model of the activity of endogenic relief-forming processes // Geomorphology, № 2, 2007, p. 37 - 48. 8. Fedorov V.M. Multidimensional analysis - is a spatiotemporal structure of the geodynamic activity of Earth// Vestnik Moskovskogo Universiteta; Ser. 4. Geology, № 4, 2007, p. 24-31.
Blank, H.J. de
2004-03-15
The motion of charged particles in slowly varying electromagnetic fields is analyzed. The strength of the magnetic field is such that the gyro-period and the gyro-radius of the particle motion around field lines are the shortest time and length scales of the system. The particle motion is described as the sum of a fast gyro-motion and a slow drift velocity.
ERIC Educational Resources Information Center
Damonte, Kathleen
2004-01-01
One thing scientists study is how objects move. A famous scientist named Sir Isaac Newton (1642-1727) spent a lot of time observing objects in motion and came up with three laws that describe how things move. This explanation only deals with the first of his three laws of motion. Newton's First Law of Motion says that moving objects will continue…
A multidimensional finite element method for CFD
NASA Technical Reports Server (NTRS)
Pepper, Darrell W.; Humphrey, Joseph W.
1991-01-01
A finite element method is used to solve the equations of motion for 2- and 3-D fluid flow. The time-dependent equations are solved explicitly using quadrilateral (2-D) and hexahedral (3-D) elements, mass lumping, and reduced integration. A Petrov-Galerkin technique is applied to the advection terms. The method requires a minimum of computational storage, executes quickly, and is scalable for execution on computer systems ranging from PCs to supercomputers.
Multidimensional radiative effects in supercritical shocks
NASA Astrophysics Data System (ADS)
Leygnac, S.; Lanz, T.; Stehlé, C.; Michaut, C.; Korĉáková, D.
Recent radiative shocks experiments performed on the LULI laser at Ecole Polytechnique in France (Fleury et al., Lasers and Particle Beams 20, 263, 2002) put in evidence a supercritical shock wave in a xenon gas cell. The structure of these shocks is quite similar to those of accretion shock wave in the case of stellar formation, as indicated in Stehlé and Chieze (SF2A - Paris proceedings, 2002). Some points require further studies like the contribution of the gas excitation/ionization energy to the compression ratio and the understanding of the discrepancy, which was noted between the velocity of the radiative precursor in the experiment and in the 1D simulation. Thus, to understand the physics of the radiative shock waves, the academic case of the stationary shock is particularly interesting. We have thus studied the structure of a radiative shock wave which propagates in an ionized gas. We study the extended Rankine Hugoniot equations in various media with inclusion of radiation pressure and energy and study also the extension of the radiative precursor in the diffusion approximation. We also study the equations of multidimensional radiative transfer for a snapshot of the experimental shock in xenon in order to quantify the radiative losses in the finite experimental cell. This academic approach will help to improve the knowledge of the physical processes which take place in radiative shocks of astrophysical interest, like in the birth and death of stars, and prepare ourselves to define appropriate experiments on future high power lasers like LIL and LMJ in Bordeaux.
Information theoretic approaches to multidimensional neural computations
NASA Astrophysics Data System (ADS)
Fitzgerald, Jeffrey D.
Many systems in nature process information by transforming inputs from their environments into observable output states. These systems are often difficult to study because they are performing computations on multidimensional inputs with many degrees of freedom using highly nonlinear functions. The work presented in this dissertation deals with some of the issues involved with characterizing real-world input/output systems and understanding the properties of idealized systems using information theoretic methods. Using the principle of maximum entropy, a family of models are created that are consistent with certain measurable correlations from an input/output dataset but are maximally unbiased in all other respects, thereby eliminating all unjustified assumptions about the computation. In certain cases, including spiking neurons, we show that these models also minimize the mutual information. This property gives one the advantage of being able to identify the relevant input/output statistics by calculating their information content. We argue that these maximum entropy models provide a much needed quantitative framework for characterizing and understanding sensory processing neurons that are selective for multiple stimulus features. To demonstrate their usefulness, these ideas are applied to neural recordings from macaque retina and thalamus. These neurons, which primarily respond to two stimulus features, are shown to be well described using only first and second order statistics, indicating that their firing rates encode information about stimulus correlations. In addition to modeling multi-feature computations in the relevant feature space, we also show that maximum entropy models are capable of discovering the relevant feature space themselves. This technique overcomes the disadvantages of two commonly used dimensionality reduction methods and is explored using several simulated neurons, as well as retinal and thalamic recordings. Finally, we ask how neurons in a
SAGE - MULTIDIMENSIONAL SELF-ADAPTIVE GRID CODE
NASA Technical Reports Server (NTRS)
Davies, C. B.
1994-01-01
SAGE, Self Adaptive Grid codE, is a flexible tool for adapting and restructuring both 2D and 3D grids. Solution-adaptive grid methods are useful tools for efficient and accurate flow predictions. In supersonic and hypersonic flows, strong gradient regions such as shocks, contact discontinuities, shear layers, etc., require careful distribution of grid points to minimize grid error and produce accurate flow-field predictions. SAGE helps the user obtain more accurate solutions by intelligently redistributing (i.e. adapting) the original grid points based on an initial or interim flow-field solution. The user then computes a new solution using the adapted grid as input to the flow solver. The adaptive-grid methodology poses the problem in an algebraic, unidirectional manner for multi-dimensional adaptations. The procedure is analogous to applying tension and torsion spring forces proportional to the local flow gradient at every grid point and finding the equilibrium position of the resulting system of grid points. The multi-dimensional problem of grid adaption is split into a series of one-dimensional problems along the computational coordinate lines. The reduced one dimensional problem then requires a tridiagonal solver to find the location of grid points along a coordinate line. Multi-directional adaption is achieved by the sequential application of the method in each coordinate direction. The tension forces direct the redistribution of points to the strong gradient region. To maintain smoothness and a measure of orthogonality of grid lines, torsional forces are introduced that relate information between the family of lines adjacent to one another. The smoothness and orthogonality constraints are direction-dependent, since they relate only the coordinate lines that are being adapted to the neighboring lines that have already been adapted. Therefore the solutions are non-unique and depend on the order and direction of adaption. Non-uniqueness of the adapted grid is
Discovering hierarchical motion structure.
Gershman, Samuel J; Tenenbaum, Joshua B; Jäkel, Frank
2016-09-01
Scenes filled with moving objects are often hierarchically organized: the motion of a migrating goose is nested within the flight pattern of its flock, the motion of a car is nested within the traffic pattern of other cars on the road, the motion of body parts are nested in the motion of the body. Humans perceive hierarchical structure even in stimuli with two or three moving dots. An influential theory of hierarchical motion perception holds that the visual system performs a "vector analysis" of moving objects, decomposing them into common and relative motions. However, this theory does not specify how to resolve ambiguity when a scene admits more than one vector analysis. We describe a Bayesian theory of vector analysis and show that it can account for classic results from dot motion experiments, as well as new experimental data. Our theory takes a step towards understanding how moving scenes are parsed into objects. PMID:25818905
Multidimensional data encryption with virtual optics
NASA Astrophysics Data System (ADS)
Yu, Lingfeng
Information security is very important in many application areas in the field of information technology. Recently, a number of optical encryption methods have been proposed for the purpose of information hiding and data security, because optical information processing techniques have obvious advantages such as high degrees of freedom (e.g. amplitude, phase, polarization, wavelength) for encryption and decryption, and high-level data security. However, the limitations of current optical encryption methods relate to the complexity of their optical hardware, the requirements of the information type, lack of flexibility, and the lack of compact and low-cost optoelectronics devices and systems. These problems make it difficult to move optical encryption out of the research lab and into real world application areas. In this thesis, a novel parameterized multidimensional data encryption method based on the concept of "virtual optics" is proposed. A strong motivation for the research in this thesis is to overcome the abovementioned problems currently existing in optical encryption and to retain most of the favorable features of optical encryption. The phrase "virtual optics" means that both the optical encryption and decryption processes are implemented in an all-digital manner, adopting optical information processing technologies such as optical holography, optical diffraction or other relevant optical processes. In addition to utilizing some geometric and physical parameters derived from a configuration of digital optics, some information disarrangement actions have also been suggested as tools for designing multiple locks and keys for data encryption in hyperspace. The sensitivities of these supposed keys are quantitatively analyzed and the possible security level of the proposed cryptosystem is assessed. Security of the cryptosystem is also analyzed by examining some possible attacks on the cryptosystem from the viewpoint of a cryptanalysis. This thesis has shown the
Quantum and Multidimensional Explanations in a Neurobiological Context of Mind.
Korf, Jakob
2015-08-01
This article examines the possible relevance of physical-mathematical multidimensional or quantum concepts aiming at understanding the (human) mind in a neurobiological context. Some typical features of the quantum and multidimensional concepts are briefly introduced, including entanglement, superposition, holonomic, and quantum field theories. Next, we consider neurobiological principles, such as the brain and its emerging (physical) mind, evolutionary and ontological origins, entropy, syntropy/neg-entropy, causation, and brain energy metabolism. In many biological processes, including biochemical conversions, protein folding, and sensory perception, the ubiquitous involvement of quantum mechanisms is well recognized. Quantum and multidimensional approaches might be expected to help describe and model both brain and mental processes, but an understanding of their direct involvement in mental activity, that is, without mediation by molecular processes, remains elusive. More work has to be done to bridge the gap between current neurobiological and physical-mathematical concepts with their associated quantum-mind theories. PMID:25049264
Graphical Representation of Proximity Measures for Multidimensional Data
Zand, Martin S.; Wang, Jiong; Hilchey, Shannon
2015-01-01
We describe the use of classical and metric multidimensional scaling methods for graphical representation of the proximity between collections of data consisting of cases characterized by multidimensional attributes. These methods can preserve metric differences between cases, while allowing for dimensional reduction and projection to two or three dimensions ideal for data exploration. We demonstrate these methods with three datasets for: (i) the immunological similarity of influenza proteins measured by a multidimensional assay; (ii) influenza protein sequence similarity; and (iii) reconstruction of airport-relative locations from paired proximity measurements. These examples highlight the use of proximity matrices, eigenvalues, eigenvectors, and linear and nonlinear mappings using numerical minimization methods. Some considerations and caveats for each method are also discussed, and compact Mathematica programs are provided. PMID:26692757
NASA Technical Reports Server (NTRS)
1994-01-01
Integrated Sensors, Inc. (ISI), under NASA contract, developed a sensor system for controlling robot vehicles. This technology would enable a robot supply vehicle to automatically dock with Earth-orbiting satellites or the International Space Station. During the docking phase the ISI-developed sensor must sense the satellite's relative motion, then spin so the robot vehicle can adjust its motion to align with the satellite and slowly close until docking is completed. ISI used the sensing/tracking technology as the basis of its OPAD system, which simultaneously tracks an object's movement in six degrees of freedom. Applications include human limb motion analysis, assembly line position analysis and auto crash dummy motion analysis. The NASA technology is also the basis for Motion Analysis Workstation software, a package to simplify the video motion analysis process.
Fast Packet Classification Using Multi-Dimensional Encoding
NASA Astrophysics Data System (ADS)
Huang, Chi Jia; Chen, Chien
Internet routers need to classify incoming packets quickly into flows in order to support features such as Internet security, virtual private networks and Quality of Service (QoS). Packet classification uses information contained in the packet header, and a predefined rule table in the routers. Packet classification of multiple fields is generally a difficult problem. Hence, researchers have proposed various algorithms. This study proposes a multi-dimensional encoding method in which parameters such as the source IP address, destination IP address, source port, destination port and protocol type are placed in a multi-dimensional space. Similar to the previously best known algorithm, i.e., bitmap intersection, multi-dimensional encoding is based on the multi-dimensional range lookup approach, in which rules are divided into several multi-dimensional collision-free rule sets. These sets are then used to form the new coding vector to replace the bit vector of the bitmap intersection algorithm. The average memory storage of this encoding is Θ (L · N · log N) for each dimension, where L denotes the number of collision-free rule sets, and N represents the number of rules. The multi-dimensional encoding practically requires much less memory than bitmap intersection algorithm. Additionally, the computation needed for this encoding is as simple as bitmap intersection algorithm. The low memory requirement of the proposed scheme means that it not only decreases the cost of packet classification engine, but also increases the classification performance, since memory represents the performance bottleneck in the packet classification engine implementation using a network processor.
NASA Technical Reports Server (NTRS)
Park, Brian Vandellyn
1993-01-01
The Neutral Body Posture experienced in microgravity creates a biomechanical equilibrium by enabling the internal forces within the body to find their own balance. A patented reclining chair based on this posture provides a minimal stress environment for interfacing with computer systems for extended periods. When the chair is mounted on a 3 or 6 axis motion platform, a generic motion simulator for simulated digital environments is created. The Personal Motion Platform provides motional feedback to the occupant in synchronization with their movements inside the digital world which enhances the simulation experience. Existing HMD based simulation systems can be integrated to the turnkey system. Future developments are discussed.
Multidimensional optical fractionation with holographic verification
NASA Astrophysics Data System (ADS)
Xiao, Ke; Grier, David
2010-03-01
Colloidal particles driven through a periodic potential energy landscape can become kinetically locked in to symmetry-selected directions. The path a given particle follows has been predicted to depend sensitively on such properties as the particle's size and refractive index. These predictions, however, have not been tested experimentally. We present experimental observations of colloidal silica spheres' trajectories through specially structured arrays of holographic optical traps, using quantitative methods of holographic video microscopy to track the particles' motions in three dimensions and simultaneously to measure their radii and refractive indexes with part-per-thousand resolution. Single-particle tracking and characterization enable us to demonstrate sorting of colloidal particles into spatially separated fractions with part-per-thousand resolution in either particle size or refractive index. Even more dramatically, these results agree quantitatively with previously untested predictions for the threshold of kinetically locked-in transport.
Measurement Error, Multidimensionality, and Scale Shrinkage: A Reply to Yen and Burket.
ERIC Educational Resources Information Center
Camilli, Gregory
1999-01-01
Yen and Burket suggested that shrinkage in vertical equating cannot be understood apart from multidimensionality. Reviews research on reliability, multidimensionality, and scale shrinkage, and explores issues of practical importance to educators. (SLD)
NASA Astrophysics Data System (ADS)
Calogero, F.; Françoise, J.-P.; Sommacal, M.
2007-05-01
A solvable nonlinear (system of) evolution PDEs in multidimensional space, involving trigonometric (or hyperbolic) functions, is identified. An isochronous version of this (system of) evolution PDEs in multidimensional space is also reported.
Ishizaki, Akihito; Tanimura, Yoshitaka
2006-08-28
Starting from a system-bath Hamiltonian in a molecular coordinate representation, we examine an applicability of a stochastic multilevel model for vibrational dephasing and energy relaxation in multidimensional infrared spectroscopy. We consider an intramolecular anharmonic mode nonlinearly coupled to a colored noise bath at finite temperature. The system-bath interaction is assumed linear plus square in the system coordinate, but linear in the bath coordinates. The square-linear system-bath interaction leads to dephasing due to the frequency fluctuation of system vibration, while the linear-linear interaction contributes to energy relaxation and a part of dephasing arises from anharmonicity. To clarify the role and origin of vibrational dephasing and energy relaxation in the stochastic model, the system part is then transformed into an energy eigenstate representation without using the rotating wave approximation. Two-dimensional (2D) infrared spectra are then calculated by solving a low-temperature corrected quantum Fokker-Planck (LTC-QFP) equation for a colored noise bath and by the stochastic theory. In motional narrowing regime, the spectra from the stochastic model are quite different from those from the LTC-QFP. In spectral diffusion regime, however, the 2D line shapes from the stochastic model resemble those from the LTC-QFP besides the blueshifts caused by the dissipation from the colored noise bath. The preconditions for validity of the stochastic theory for molecular vibrational motion are also discussed. PMID:16965023
Multidimensional modal analysis of nonlinear sloshing in a rectangular tank with finite water depth
NASA Astrophysics Data System (ADS)
Faltinsen, Odd M.; Rognebakke, Olav F.; Lukovsky, Ivan A.; Timokha, Alexander N.
2000-03-01
The discrete infinite-dimensional modal system describing nonlinear sloshing of an incompressible fluid with irrotational flow partially occupying a tank performing an arbitrary three-dimensional motion is derived in general form. The tank has vertical walls near the free surface and overturning waves are excluded. The derivation is based on the Bateman Luke variational principle. The free surface motion and velocity potential are expanded in generalized Fourier series. The derived infinite-dimensional modal system couples generalized time-dependent coordinates of free surface elevation and the velocity potential. The procedure is not restricted by any order of smallness. The general multidimensional structure of the equations is approximated to analyse sloshing in a rectangular tank with finite water depth. The amplitude frequency response is consistent with the fifth-order steady-state solutions by Waterhouse (1994). The theory is validated by new experimental results. It is shown that transients and associated nonlinear beating are important. An initial variation of excitation periods is more important than initial conditions. The theory is invalid when either the water depth is small or water impacts heavily on the tank ceiling. Alternative expressions for hydrodynamic loads are presented. The procedure facilitates simulations of a coupled vehicle fluid system.
Motion compensator for holographic motion picture camera
NASA Technical Reports Server (NTRS)
Kurtz, R. L.
1973-01-01
When reference beam strikes target it undergoes Doppler shift dependent upon target velocity. To compensate, object beam is first reflected from rotating cylinder that revolves in direction opposite to target but at same speed. When beam strikes target it is returned to original frequency and is in phase with reference beam. Alternatively this motion compensator may act on reference beam.
NASA Technical Reports Server (NTRS)
Dimeff, J.; Rositano, S.; Taylor, R. C.
1977-01-01
Mandibular motion along three axes is measured by three motion transducers on floating yoke that rests against mandible. System includes electronics to provide variety of outputs for data display and processing. Head frame is strapped to test subject's skull to provide fixed point of reference for transducers.
NASA Technical Reports Server (NTRS)
1974-01-01
The use of optical data processing (ODP) techniques for motion analysis in two-dimensional imagery was studied. The basic feasibility of this approach was demonstrated, but inconsistent performance of the photoplastic used for recording spatial filters prevented totally automatic operation. Promising solutions to the problems encountered are discussed, and it is concluded that ODP techniques could be quite useful for motion analysis.
ERIC Educational Resources Information Center
Ashbrook, Peggy
2008-01-01
Objects in motion attract children. The following activity helps children explore the motion of bodies riding in a vehicle and safely demonstrates the answer to their questions, "Why do I need a seatbelt?" Children will enjoy moving the cup around, even if all they "see" is a cup rather than understanding it represents a car. They will understand…
ERIC Educational Resources Information Center
Nemirovsky, Ricardo; Tierney, Cornelia; Wright, Tracy
1998-01-01
Analyzed two children's use of a computer-based motion detector to make sense of symbolic expressions (Cartesian graphs). Found three themes: (1) tool perspectives, efforts to understand graphical responses to body motion; (2) fusion, emergent ways of talking and behaving that merge symbols and referents; and (3) graphical spaces, when changing…
ERIC Educational Resources Information Center
Summers, M. K.
1977-01-01
Described is a novel approach to the teaching of projectile motion of sixth form level. Students are asked to use an analogue circuit to observe projectile motion and to graph the experimental results. Using knowledge of basic dynamics, students are asked to explain the shape of the curves theoretically. (Author/MA)
Motion through Syntactic Frames
ERIC Educational Resources Information Center
Feist, Michele I.
2010-01-01
The introduction of (Talmy, 1985), (Talmy, 1985) and (Talmy, 2000) typology sparked significant interest in linguistic relativity in the arena of motion language. Through careful analysis of the conflation patterns evident in the language of motion events, Talmy noted that one class of languages, V-languages, tends to encode path along with the…
Aristotle, Motion, and Rhetoric.
ERIC Educational Resources Information Center
Sutton, Jane
Aristotle rejects a world vision of changing reality as neither useful nor beneficial to human life, and instead he reaffirms both change and eternal reality, fuses motion and rest, and ends up with "well-behaved" changes. This concept of motion is foundational to his world view, and from it emerges his theory of knowledge, philosophy of nature,…
ERIC Educational Resources Information Center
King, Kenneth
2005-01-01
When watching a small child with a toy car, it is seen that interest in motion comes early. Children often suggest speed through sounds such as "RRRrrrRRRooooommMMMmmmm" as the toy car is made to speed up, slow down, or accelerate through a turn. Older children start to consider force and motion studies in more detail, and experiences in school…
ERIC Educational Resources Information Center
McCloskey, Michael
Everyday life provides individuals with countless opportunities for observing and interacting with objects in motion. Although everyone presumably has some sort of knowledge about motion, it is by no means clear what form(s) this knowledge may take. The research described in this paper determined what sorts of knowledge are in fact acquired…
41 CFR 60-30.8 - Motions; disposition of motions.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Motions; disposition of motions. 60-30.8 Section 60-30.8 Public Contracts and Property Management Other Provisions Relating to... EXECUTIVE ORDER 11246 Prehearing Procedures § 60-30.8 Motions; disposition of motions. (a) Motions....
41 CFR 60-30.8 - Motions; disposition of motions.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 false Motions; disposition of motions. 60-30.8 Section 60-30.8 Public Contracts and Property Management Other Provisions Relating to... EXECUTIVE ORDER 11246 Prehearing Procedures § 60-30.8 Motions; disposition of motions. (a) Motions....
41 CFR 60-30.8 - Motions; disposition of motions.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 41 Public Contracts and Property Management 1 2011-07-01 2009-07-01 true Motions; disposition of motions. 60-30.8 Section 60-30.8 Public Contracts and Property Management Other Provisions Relating to... EXECUTIVE ORDER 11246 Prehearing Procedures § 60-30.8 Motions; disposition of motions. (a) Motions....
41 CFR 60-30.8 - Motions; disposition of motions.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 41 Public Contracts and Property Management 1 2012-07-01 2009-07-01 true Motions; disposition of motions. 60-30.8 Section 60-30.8 Public Contracts and Property Management Other Provisions Relating to... EXECUTIVE ORDER 11246 Prehearing Procedures § 60-30.8 Motions; disposition of motions. (a) Motions....
41 CFR 60-30.8 - Motions; disposition of motions.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 41 Public Contracts and Property Management 1 2013-07-01 2013-07-01 false Motions; disposition of motions. 60-30.8 Section 60-30.8 Public Contracts and Property Management Other Provisions Relating to... EXECUTIVE ORDER 11246 Prehearing Procedures § 60-30.8 Motions; disposition of motions. (a) Motions....
Multidimensional Measurement of Poverty among Women in Sub-Saharan Africa
ERIC Educational Resources Information Center
Batana, Yele Maweki
2013-01-01
Since the seminal work of Sen, poverty has been recognized as a multidimensional phenomenon. The recent availability of relevant databases renewed the interest in this approach. This paper estimates multidimensional poverty among women in fourteen Sub-Saharan African countries using the Alkire and Foster multidimensional poverty measures, whose…
Best Design for Multidimensional Computerized Adaptive Testing with the Bifactor Model
ERIC Educational Resources Information Center
Seo, Dong Gi; Weiss, David J.
2015-01-01
Most computerized adaptive tests (CATs) have been studied using the framework of unidimensional item response theory. However, many psychological variables are multidimensional and might benefit from using a multidimensional approach to CATs. This study investigated the accuracy, fidelity, and efficiency of a fully multidimensional CAT algorithm…
Brownian motion goes ballistic
NASA Astrophysics Data System (ADS)
Florin, Ernst-Ludwig
2012-02-01
It is the randomness that is considered the hallmark of Brownian motion, but already in Einstein's seminal 1905 paper on Brownian motion it is implied that this randomness must break down at short time scales when the inertia of the particle kicks in. As a result, the particle's trajectories should lose its randomness and become smooth. The characteristic time scale for this transition is given by the ratio of the particle's mass to its viscous drag coefficient. For a 1 μm glass particle in water and at room temperature, this timescale is on the order of 100 ns. Early calculations, however, neglected the inertia of the liquid surrounding the particle which induces a transition from random diffusive to non-diffusive Brownian motion already at much larger timescales. In this first non-diffusive regime, particles of the same size but with different densities still move at almost the same rate as a result of hydrodynamic correlations. To observe Brownian motion that is dominated by the inertia of the particle, i.e. ballistic motion, one has to observe the particle at significantly shorter time scales on the order of nanoseconds. Due to the lack of sufficiently fast and precise detectors, such experiments were so far not possible on individual particles. I will describe how we were able to observe the transition from hydrodynamically dominated Brownian motion to ballistic Brownian motion in a liquid. I will compare our data with current theories for Brownian motion on fast timescales that take into account the inertia of both the liquid and the particle. The newly gained ability to measure the fast Brownian motion of an individual particle paves the way for detailed studies of confined Brownian motion and Brownian motion in heterogeneous media. [4pt] [1] Einstein, A. "Uber die von der molekularkinetischen Theorie der W"arme geforderte Bewegung von in ruhenden Fl"ussigkeiten suspendierten Teilchen. Ann. Phys. 322, 549--560 (1905). [0pt] [2] Lukic, B., S. Jeney, C
Ducommun, Christine Y; Michel, Christoph M; Clarke, Stephanie; Adriani, Michela; Seeck, Margitta; Landis, Theodor; Blanke, Olaf
2004-09-16
The extent to which the auditory system, like the visual system, processes spatial stimulus characteristics such as location and motion in separate specialized neuronal modules or in one homogeneously distributed network is unresolved. Here we present a patient with a selective deficit for the perception and discrimination of auditory motion following resection of the right anterior temporal lobe and the right posterior superior temporal gyrus (STG). Analysis of stimulus identity and location within the auditory scene remained intact. In addition, intracranial auditory evoked potentials, recorded preoperatively, revealed motion-specific responses selectively over the resected right posterior STG, and electrical cortical stimulation of this region was experienced by the patient as incoming moving sounds. Collectively, these data present a patient with cortical motion deafness, providing evidence that cortical processing of auditory motion is performed in a specialized module within the posterior STG. PMID:15363389
Stochastic ground motion simulation
Rezaeian, Sanaz; Xiaodan, Sun
2014-01-01
Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.
Deriving Stopping Rules for Multidimensional Computerized Adaptive Testing
ERIC Educational Resources Information Center
Wang, Chun; Chang, Hua-Hua; Boughton, Keith A.
2013-01-01
Multidimensional computerized adaptive testing (MCAT) is able to provide a vector of ability estimates for each examinee, which could be used to provide a more informative profile of an examinee's performance. The current literature on MCAT focuses on the fixed-length tests, which can generate less accurate results for those examinees whose…
Multidimensional Scaling versus Components Analysis of Test Intercorrelations.
ERIC Educational Resources Information Center
Davison, Mark L.
1985-01-01
Considers the relationship between coordinate estimates in components analysis and multidimensional scaling. Reports three small Monte Carlo studies comparing nonmetric scaling solutions to components analysis. Results are related to other methodological issues surrounding research on the general ability factor, response tendencies in…
Multidimensional Scaling: Review and Geographical Applications, Technical Paper No. 10.
ERIC Educational Resources Information Center
Golledge, R. G.; Rushton, Gerard
The purpose of this monograph is to show that sufficient achievements in scaling applications have been made to justify serious study of scaling methodologies, particularly multidimensional scaling (MDS) as a tool for geographers. To be useful research, it was felt that the common methodological and technical problems that specialized researchers…
Multidimensional Scoring of Abilities: The Ordered Polytomous Response Case
ERIC Educational Resources Information Center
de la Torre, Jimmy
2008-01-01
Recent work has shown that multidimensionally scoring responses from different tests can provide better ability estimates. For educational assessment data, applications of this approach have been limited to binary scores. Of the different variants, the de la Torre and Patz model is considered more general because implementing the scoring procedure…
A Framework for Dimensionality Assessment for Multidimensional Item Response Models
ERIC Educational Resources Information Center
Svetina, Dubravka; Levy, Roy
2014-01-01
A framework is introduced for considering dimensionality assessment procedures for multidimensional item response models. The framework characterizes procedures in terms of their confirmatory or exploratory approach, parametric or nonparametric assumptions, and applicability to dichotomous, polytomous, and missing data. Popular and emerging…
Development and Validation of the Multidimensional State Boredom Scale
ERIC Educational Resources Information Center
Fahlman, Shelley A.; Mercer-Lynn, Kimberley B.; Flora, David B.; Eastwood, John D.
2013-01-01
This article describes the development and validation of the Multidimensional State Boredom Scale (MSBS)--the first and only full-scale measure of state boredom. It was developed based on a theoretically and empirically grounded definition of boredom. A five-factor structure of the scale (Disengagement, High Arousal, Low Arousal, Inattention, and…
Multidimensional Poverty in China: Findings Based on the CHNS
ERIC Educational Resources Information Center
Yu, Jiantuo
2013-01-01
This paper estimates multidimensional poverty in China by applying the Alkire-Foster methodology to the China Health and Nutrition Survey 2000-2009 data. Five dimensions are included: income, living standard, education, health and social security. Results suggest that rapid economic growth has resulted not only in a reduction in income poverty but…
Income and beyond: Multidimensional Poverty in Six Latin American Countries
ERIC Educational Resources Information Center
Battiston, Diego; Cruces, Guillermo; Lopez-Calva, Luis Felipe; Lugo, Maria Ana; Santos, Maria Emma
2013-01-01
This paper studies multidimensional poverty for Argentina, Brazil, Chile, El Salvador, Mexico and Uruguay for the period 1992-2006. The approach overcomes the limitations of the two traditional methods of poverty analysis in Latin America (income-based and unmet basic needs) by combining income with five other dimensions: school attendance for…
Multidimensional Vector Model of Stimulus-Response Compatibility
ERIC Educational Resources Information Center
Yamaguchi, Motonori; Proctor, Robert W.
2012-01-01
The present study proposes and examines the multidimensional vector (MDV) model framework as a modeling schema for choice response times. MDV extends the Thurstonian model, as well as signal detection theory, to classification tasks by taking into account the influence of response properties on stimulus discrimination. It is capable of accounting…
A Review of the Brief Multidimensional Students' Life Satisfaction Scale
ERIC Educational Resources Information Center
Huebner, E. Scott; Seligson, Julie L.; Valois, Robert F.; Suldo, Shannon M.
2006-01-01
There are few psychometrically sound measures of life satisfaction suitable for children and adolescents. The purpose of this paper is to describe the rationale, development, and psychometric properties of a brief multidimensional life satisfaction scale appropriate for use with children of ages 8-18. The paper summarizes extant studies of its…
Multidimensional Model of Trauma and Correlated Antisocial Personality Disorder
ERIC Educational Resources Information Center
Martens, Willem H. J.
2005-01-01
Many studies have revealed an important relationship between psychosocial trauma and antisocial personality disorder. A multidimensional model is presented which describes the psychopathological route from trauma to antisocial development. A case report is also included that can illustrate the etiological process from trauma to severe antisocial…
A MULTIDIMENSIONAL AND MULTIPHYSICS APPROACH TO NUCLEAR FUEL BEHAVIOR SIMULATION
R. L. Williamson; J. D. Hales; S. R. Novascone; M. R. Tonks; D. R. Gaston; C. J. Permann; D. Andrs; R. C. Martineau
2012-04-01
Important aspects of fuel rod behavior, for example pellet-clad mechanical interaction (PCMI), fuel fracture, oxide formation, non-axisymmetric cooling, and response to fuel manufacturing defects, are inherently multidimensional in addition to being complicated multiphysics problems. Many current modeling tools are strictly 2D axisymmetric or even 1.5D. This paper outlines the capabilities of a new fuel modeling tool able to analyze either 2D axisymmetric or fully 3D models. These capabilities include temperature-dependent thermal conductivity of fuel; swelling and densification; fuel creep; pellet fracture; fission gas release; cladding creep; irradiation growth; and gap mechanics (contact and gap heat transfer). The need for multiphysics, multidimensional modeling is then demonstrated through a discussion of results for a set of example problems. The first, a 10-pellet rodlet, demonstrates the viability of the solution method employed. This example highlights the effect of our smeared cracking model and also shows the multidimensional nature of discrete fuel pellet modeling. The second example relies on our the multidimensional, multiphysics approach to analyze a missing pellet surface problem. As a final example, we show a lower-length-scale simulation coupled to a continuum-scale simulation.
Multidimensional Scaling of High School Students' Perceptions of Academic Dishonesty
ERIC Educational Resources Information Center
Schmelkin, Liora Pedhazur; Gilbert, Kimberly A.; Silva, Rebecca
2010-01-01
Although cheating on tests and other forms of academic dishonesty are considered rampant, no standard definition of academic dishonesty exists. The current study was conducted to investigate the perceptions of academic dishonesty in high school students, utilizing an innovative methodology, multidimensional scaling (MDS). Two methods were used to…
The Structure and Validity of the Multidimensional Social Support Questionnaire
ERIC Educational Resources Information Center
Hardesty, Patrick H.; Richardson, George B.
2012-01-01
The factor structure and concurrent validity of the Multidimensional Social Support Questionnaire, a brief measure of perceived social support for use with adolescents, was examined. Findings suggest that four dimensions of perceived social support may yield more information than assessments of the unitary construct of support. (Contains 8 tables…
An overview of multidimensional liquid phase separations in food analysis.
Franco, Maraíssa Silva; Padovan, Rodrigo Nogueira; Fumes, Bruno Henrique; Lanças, Fernando Mauro
2016-07-01
Food safety is a priority public health concern that demands analytical methods capable to detect low concentration level of contaminants (e.g. pesticides and antibiotics) in different food matrices. Due to the high complexity of these matrices, a sample preparation step is in most cases mandatory to achieve satisfactory results being usually tedious, lengthy, and prone to the introduction of errors. For this reason, many research groups have focused efforts on the development of online systems capable to do the cleanup, concentration, and separation steps at once through multidimensional separation techniques (MDS). Among several possible setups, the most popular are the multidimensional chromatographic techniques (MDC) that consist in combining more than one mobile and/or stationary phase to provide a satisfactory separation. In the present review, we selected a variety of multidimensional separation systems used for food contaminant analysis in order to discuss the instrumentation aspects, the concept of orthogonality, column approaches used in these systems, and new materials that can be used in these columns. Selected classes of contaminants present in food matrices are introduced and discussed as example of the potential applications of multidimensional liquid phase separation techniques in food safety. PMID:27030380
ERIC Educational Resources Information Center
Ding, Cody
2012-01-01
There has been considerable debate over the ways in which children's early literacy skills develop over time. Using confirmatory multidimensional scaling (MDS) growth analysis, this paper directly tested the hypothesis of a cumulative trajectory versus a compensatory trajectory of development in early literacy skills among a group of 1233…
Evaluation of Linking Methods for Multidimensional IRT Calibrations
ERIC Educational Resources Information Center
Min, Kyung-Seok
2007-01-01
Most researchers agree that psychological/educational tests are sensitive to multiple traits, implying the need for a multidimensional item response theory (MIRT). One limitation of applying a MIRT in practice is the difficulty in establishing equivalent scales of multiple traits. In this study, a new MIRT linking method was proposed and evaluated…
BMDS: A Collection of R Functions for Bayesian Multidimensional Scaling
ERIC Educational Resources Information Center
Okada, Kensuke; Shigemasu, Kazuo
2009-01-01
Bayesian multidimensional scaling (MDS) has attracted a great deal of attention because: (1) it provides a better fit than do classical MDS and ALSCAL; (2) it provides estimation errors of the distances; and (3) the Bayesian dimension selection criterion, MDSIC, provides a direct indication of optimal dimensionality. However, Bayesian MDS is not…
Mental Models of Text and Film: A Multidimensional Scaling Analysis.
ERIC Educational Resources Information Center
Rowell, Jack A.; Moss, Peter D.
1986-01-01
Reports results of experiment to determine whether mental models are constructed of interrelationships and cross-relationships of character attributions drawn in themes of novels and films. The study used "Animal Farm" in print and cartoon forms. Results demonstrated validity of multidimensional scaling for representing both media. Proposes use of…
The Relationship between Anxiety and Stuttering: A Multidimensional Approach
ERIC Educational Resources Information Center
Ezrati-Vinacour, Ruth; Levin, Iris
2004-01-01
The relationship between anxiety and stuttering is equivocal from both clinical and empirical perspectives. This study examined the relationship within the framework of the multidimensional interaction model of anxiety that includes an approach to general anxiety in specific situations [J. Pers. Soc. Psychol. 60 (1991) 919]. Ninety-four males aged…
Turkish Validity Examination of the Multidimensional Students' Life Satisfaction Scale
ERIC Educational Resources Information Center
Irmak, Sezgin; Kuruuzum, Ayse
2009-01-01
The validation studies of the Multidimensional Students' Life Satisfaction Scale (MSLSS) have been conducted with samples from different nations but mostly from western individualistic cultures. Life satisfaction and its constructs could differ depending on cultural characteristics and life satisfaction scales should be validated in different…
Multidimensional Assessment of Phonological Similarity within and between Children
ERIC Educational Resources Information Center
Ingram, David; Dubasik, Virginia L.
2011-01-01
Multidimensional analysis involves moving away from one-dimensional analyses such as most articulation tests to comprehensive analyses involving levels of phonological information from the word level down to segments. This article outlines one such approach that looks at four levels from words to segments, using nine phonological measures. It also…
Structure of classical trajectories in multidimensional bound molecular systems
Ashton, C.J.; Muckerman, J.T.
1983-07-21
A computational method is described which enables visualization of the coordinate space envelopes of classical trajectories in multidimensional bound molecular systems. The method is exemplified by application to a realistic three-dimensional model of the vibrating water molecule, and its utility in the application of semiclassical quantization techniques is emphasized. 8 figures.
Multidimensional Collaboration: Reflections on Action Research in a Clinical Context
ERIC Educational Resources Information Center
Gregory, Sheila; Poland, Fiona; Spalding, Nicola J.; Sargen, Kevin; McCulloch, Jane; Vicary, Penny
2011-01-01
This paper reflects on the challenges and benefits of multidimensional collaboration in an action research study to evaluate and improve preoperative education for patients awaiting colorectal surgery. Three cycles of planning, acting, observing and reflecting were designed to evaluate practice and implement change in this interactive setting,…
Generalizations of Paradoxical Results in Multidimensional Item Response Theory
ERIC Educational Resources Information Center
Jordan, Pascal; Spiess, Martin
2012-01-01
Maximum likelihood and Bayesian ability estimation in multidimensional item response models can lead to paradoxical results as proven by Hooker, Finkelman, and Schwartzman ("Psychometrika" 74(3): 419-442, 2009): Changing a correct response on one item into an incorrect response may produce a higher ability estimate in one dimension. Furthermore,…
The Measurement of Multidimensional Gender Inequality: Continuing the Debate
ERIC Educational Resources Information Center
Permanyer, Inaki
2010-01-01
The measurement of multidimensional gender inequality is an increasingly important topic that has very relevant policy applications and implications but which has not received much attention from the academic literature. In this paper I make a comprehensive and critical review of the indices proposed in recent years in order to systematise the…
A multidimensional evaluation of a nursing information-literacy program.
Fox, L M; Richter, J M; White, N E
1996-01-01
The goal of an information-literacy program is to develop student skills in locating, evaluating, and applying information for use in critical thinking and problem solving. This paper describes a multidimensional evaluation process for determining nursing students' growth in cognitive and affective domains. Results indicate improvement in student skills as a result of a nursing information-literacy program. Multidimensional evaluation produces a well-rounded picture of student progress based on formal measurement as well as informal feedback. Developing new educational programs can be a time-consuming challenge. It is important, when expending so much effort, to ensure that the goals of the new program are achieved and benefits to students demonstrated. A multidimensional approach to evaluation can help to accomplish those ends. In 1988, The University of Northern Colorado School of Nursing began working with a librarian to integrate an information-literacy component, entitled Pathways to Information Literacy, into the curriculum. This article describes the program and discusses how a multidimensional evaluation process was used to assess program effectiveness. The evaluation process not only helped to measure the effectiveness of the program but also allowed the instructors to use several different approaches to evaluation. PMID:8826621
Bayesian Multidimensional IRT Models with a Hierarchical Structure
ERIC Educational Resources Information Center
Sheng, Yanyan; Wikle, Christopher K.
2008-01-01
As item response models gain increased popularity in large-scale educational and measurement testing situations, many studies have been conducted on the development and applications of unidimensional and multidimensional models. Recently, attention has been paid to IRT-based models with an overall ability dimension underlying several ability…
Parentification of Adult Children of Divorce: A Multidimensional Analysis.
ERIC Educational Resources Information Center
Jurkovic, Gregory J.; Thirkield, Alison; Morrell, Richard
2001-01-01
Compared the responses of 381 late adolescent and young adult children of divorce and nondivorce on a new multidimensional measure of parentification assessing the extent and fairness of past and present family caregiving. Evidence that problematic forms of parentification in children of divorce continue into late adolescence and young adulthood…
Reporting of Subscores Using Multidimensional Item Response Theory
ERIC Educational Resources Information Center
Haberman, Shelby J.; Sinharay, Sandip
2010-01-01
Recently, there has been increasing interest in reporting subscores. This paper examines reporting of subscores using multidimensional item response theory (MIRT) models (e.g., Reckase in "Appl. Psychol. Meas." 21:25-36, 1997; C.R. Rao and S. Sinharay (Eds), "Handbook of Statistics, vol. 26," pp. 607-642, North-Holland, Amsterdam, 2007; Beguin &…
Conditional Covariance-based Representation of Multidimensional Test Structure.
ERIC Educational Resources Information Center
Bolt, Daniel M.
2001-01-01
Presents a new nonparametric method for constructing a spatial representation of multidimensional test structure, the Conditional Covariance-based SCALing (CCSCAL) method. Describes an index to measure the accuracy of the representation. Uses simulation and real-life data analyses to show that the method provides a suitable approximation to…