Miracle-dz/UniFAR-FTUs huggingface dataset:
RAYLEIGH-BÉNARD CONVECTION OF WATER IN A PERFECTLY CONDUCTING CUBICAL CAVITY: EFFECTS OF TEMPERATURE-DEPENDENT PHYSICAL PROPERTIES IN LAMINAR AND TURBULENT REGIMES

ABSTRACT The effects of a non-Boussinesq fluid are discussed for Rayleigh-Bénard convection in a cubical cavity with perfectly conducting side walls at low and high Rayleigh numbers using water as a convecting fluid. Non-Boussinesq simulations were calculated with a variation of 62% and 40% of the thermal expansion coefficient and viscosity, respectively, between cold and hot plates. These variations are well above the 10% usually accepted to consider the Boussinesq approximation. The overall laminar and turbulent flow topologies obtained are not significantly affected by the effects of the physical properties variation with temperature.
On the recoding of continuous and bounded indexes to a binomial form: an application to quality-of-life scores

The statistical analysis of patient-reported outcomes (PROs) as endpoints has shown to be of great practical relevance. The resulting scores or indexes from the questionnaires used to measure PROs could be treated as continuous or ordinal. The goal of this study is to propose and evaluate a recoding process of the scores, so that they can be treated as binomial outcomes and, therefore, analyzed using logistic regression with random effects. The general methodology of recoding is based on the observable values of the scores. In order to obtain an optimal recoding, the evaluation of the recoding method is tested for different values of the parameters of the binomial distribution and different probability distributions of the random effects. We illustrate, evaluate and validate the proposed method of recoding with the Short Form-36 (SF-36) Survey and real data. The optimal recoding approach is very useful and flexible. Moreover, it has a natural interpretation, not only for ordinal scores, but also for questionnaires with many dimensions and different profiles, where a common method of analysis is desired, such as the SF-36.
A new selection metric for multiobjective hydrologic model calibration

A novel selection metric called Convex Hull Contribution (CHC) is introduced for solving multiobjective (MO) optimization problems with Pareto fronts that can be accurately approximated by a convex curve. The hydrologic model calibration literature shows that many biobjective calibration problems with a proper setup result in such Pareto fronts. The CHC selection approach identifies a subset of archived nondominated solutions whose map in the objective space forms convex approximation of the Pareto front. The optimization algorithm can sample solely from these solutions to more accurately approximate the convex shape of the Pareto front. It is empirically demonstrated that CHC improves the performance of Pareto Archived Dynamically Dimensioned Search (PA‐DDS) when solving MO problems with convex Pareto fronts. This conclusion is based on the results of several benchmark mathematical problems and several hydrologic model calibration problems with two or three objective functions. The impact of CHC on PA‐DDS performance is most evident when the computational budget is somewhat limited. It is also demonstrated that 1,000 solution evaluations (limited budget in this study) is sufficient for PA‐DDS with CHC‐based selection to achieve very high quality calibration results relative to the results achieved after 10,000 solution evaluations.
Agent-based analysis of trustworthiness in wireless sensor networks

Information assurance is a critical component of any organization's data network. Trustworthiness of the sensor data, especially in the case of wireless sensor networks (WSNs), is an important metric for any application that requires situational awareness. In a WSN, information packets are typically not encrypted and the nodes themselves could be located in the open, leaving them susceptible to tampering and physical degradation. In order to develop a method to assess trustworthiness in WSNs, we have utilized statistical trustworthiness metrics and have implemented an agentbased simulation platform that can perform various trustworthiness measurement experiments for various WSN operating scenarios. Different trust metrics are used against multiple vulnerabilities to detect anomalous behavior and node failure as well as malicious attacks. The simulation platform simulates WSNs with various topologies, routing algorithms, battery and power consumption models, and various types of attacks and defense mechanisms. Additionally, we adopt information entropy based techniques to detect anomalous behavior. Finally, detection techniques are fused to provide various metrics, and various trustworthiness metrics are fused to provide aggregate trustworthiness for the purpose of situational awareness.
Classical and logic based regulator design and its complexity for partially observed automata

The problem of steering the state of a partially observed finite automaton (i.e. a partially observed deterministic finite input-state output system) M to a desired terminal state is considered. The authors provide necessary and sufficient dynamic programming conditions for the controllability of M. These conditions are stated in terms of backward recurrence equations involving the state estimate sets generated by either classical dynamical observers or logical dynamical observers. <<ETX>>
Turbulent drag reduction via a transverse wave traveling along streamwise direction induced by Lorentz force

Lorentz force can be used to induce motion in the electrically conducting fluids which might then lead to turbulence suppression and drag reduction. In this paper, drag reduction in turbulent channel flow via a transverse wave traveling along streamwise direction induced by Lorentz force is investigated numerically by direct numerical simulation. It is found that the intrinsic and induced flows are modified each other due to the two-way coupling when the transverse wavy Lorentz force is utilized to modulate the near-wall turbulent flow. There is an optimal wave number kx in flow control, in which the influence of the intrinsic flow on the induced flow is weakest, and on the contrary, the intrinsic turbulent flow is modified strongly by the induced flow. The variable-interval space averaging detective technique (a spatial version of the VITA technique) and conditionally sampled and ensemble averaging method are used to obtain the frequency and intensity of the turbulent bursts which mainly contribute to th.
Hall effects on the hydromagnetic free convective flow and mass transfer through a porous medium bounded by an infinite vertical porous plate with constant heat flux

Effects of Hall current on free convection and mass transfer flow through a porous medium bounded by a vertical surface when a uniform magnetic field acts in a plane which makes an angle x with the plane transverse to the plate have been analysed. An analytic solution of the problem is obtained and the effects of the Hall parameter and the permeability parameter, as well as the other parameters entering into the problem, are discussed and shown graphically.
On the Practical Stability of Incorporating Integral Compensation Into the Low-and-High Gain Control for a Class of Systems With Norm-Type Input Saturation

This paper studies the practical stability of incorporating integral compensation into the original low-and-high gain feedback law. The motivation for the incorporation is for achieving output regulation in the presence of constant disturbances without the use of a very large high-gain parameter required in the original approach. Due to numerical accuracy, the employment of very large high-gain parameters to eliminate steady-state error has the potential for inducing undesirable chattering effect on the control signal. A set of linear matrix inequalities is formulated in this study to obtain the related design parameters, by which the incorporation can achieve both the practical stabilization and asymptotic output regulation in the presence of input saturation and constant disturbances. Furthermore, the saturation of the control input can be shown to vanish in finite time during the process of regulation. Numerical examples are given to demonstrate the effectiveness of the proposed approach.
Passive mode locking of the cw dye laser

Passive mode locking of a cw Rhodamine 6G laser is reported. A stable continuous output of picosecond pulses has been achieved. Correlation measurements using second‐harmonic generation (SHG) have determined the pulses to be as short as 1.5 psec. The pulses are transform limited and are wavelength tunable over the range 5900–6100 A.
Tip–sample relaxation as a source of uncertainty in nanoscale scanning probe microscopy measurements

Nanoscale dimensional measurements are very often focused on small objects formed by only a few atomic layers in one or more dimensions. The classical convolution approach to tip–sample artifacts cannot be valid for these specimens due to the quantum-mechanical nature of small objects. As interatomic forces act on the sample and the tip of the microscope, the atoms of both relax in order to reach equilibrium positions. This leads to changes in those quantities that are finally interpreted as the atomic force microscope (AFM) tip position and influences the resultant dimensional measurements. In this paper, sources of uncertainty connected with tip–surface relaxation at the atomic level are discussed. Results of both density functional theory modeling and of classical molecular dynamics of AFM scans on typical systems used in nanometrology, e.g., fullerenes and carbon nanotubes, on highly oriented pyrolytic graphite substrates are presented. We study also the effects of tip–surface relaxation on critical measurements of the dimensions of these objects.
Alternative Ways of Assessing Model Fit

This article is concerned with measures of fit of a model. Two types of error involved in fitting a model are considered. The first is error of approximation which involves the fit of the model, with optimally chosen but unknown parameter values, to the population covariance matrix. The second is overall error which involves the fit of the model, with parameter values estimated from the sample, to the population covariance matrix. Measures of the two types of error are proposed and point and interval estimates of the measures are suggested. These measures take the number of parameters in the model into account in order to avoid penalizing parsimonious models. Practical difficulties associated with the usual tests of exact fit or a model are discussed and a test of “close fit” of a model is suggested.
Stabilized finite element formulations for liquid membranes and their application to droplet contact

A liquid membrane formulation is presented that is suitable to analyze liquid films and their contact behavior. The governing strong form and weak form equations are presented in the general framework of the curvilinear coordinate system that is used for the surface description of the membrane. Particular emphasis is placed on the stabilization of the in‐plane equilibrium equations, which is essential for the quasi‐static description of liquid membranes. Two new stabilization schemes are proposed that affect only the in‐plane membrane behavior while leaving the out‐of‐plane membrane behavior unaffected. Further emphasis is placed on the description of line contact needed to impose nontrivial contact angles. The proposed formulation is discretized within the finite element method considering both standard Lagrange‐based and isogeometric NURBS‐based finite elements. Computational contact algorithms are formulated both for surface and line contact. The complete linearization of the discretize formulation is given. A large range of numerical examples is presented to illustrate the different physical aspects that are captured by the proposed formulation. The examples are further used to analyze the performance of the new stabilization schemes. Copyright © 2014 John Wiley & Sons, Ltd.
Variational and statistical shape modeling for 3D geometry reconstruction

The reconstruction of geometric shapes plays an important role in many biomedical applications. One example is the patient-specific, computer-aided planning of complex interventions, which requires the generation of explicitly represented geometric models of anatomical structures from medical image data. Only solutions that require minimal interaction by medical personnel are likely to enter clinical routine. Another example is the planning of surgical corrections of deformities where the target shape is unknown. Surgeons are often forced to resort to subjective criteria. These applications still pose highly challenging reconstruction problems, which are addressed in this thesis. The fundamental hypothesis, pursued in this thesis, is that the problems can be solved by incorporating a-priori knowledge about shape and other application-specific characteristics. Here, we focus mainly on the aspect of geometric shape analysis. The basic idea is to capture the most essential variations of a certain class of geometric objects via statistical shape models, which model typical features contained in a given population, and restrict the outcome of a reconstruction algorithm (more or less) to the space spanned by such models. A fundamental prerequisite for performing statistical shape analysis on a set of different objects is the identification of corresponding points on their associated surfaces. This problem is particularly difficult to solve if the shapes stem from different individuals. The reason lies in the basic difficulty of defining suitable measures of similarity. In this thesis, we divide the correspondence problem into feature and non-feature matching. The feature part depends on the application, while the non-feature part can be characterized by a purely geometric description. We propose two different approaches. The first approach has proved useful in many applications. Yet, it suffers from some practical limitations and does not yield a measure of similarity. Our second, variational, approach is designed to overcome these limitations. In it, we propose to minimize an invariant stretching measure, constrained by previously computed features. An important property, which sets our method apart from previous work, is that it does not require the computation of a global surface parameterization.
Bringing Large Technology Systems to Economic Maturity: The role of technology management

For long periods after their introductions, all big technologies have failed to create the kinds of productivity improvements that they would deliver in the long run. Many large technology systems today show the kinds of weaknesses found in the immature periods of earlier technologies such as those apparent in 18 Century steam-driven factories and early 20 Century factories where electric motors were added to steam-based systems. Users of today’s systems often spend significant amounts of time struggling with functions and interfaces that work poorly. Yet today a few large systems do work with the kind of smooth reliability and comprehensiveness of function that supported economic takeoffs when comparable functionality was reached in the past. (The systems of Amazon.com and of some big box retailers seem to be examples.) This paper argues that such systems emerge through processes that are: 1) very long-term. They require multiple decades. 2) organization-wide. Rather than being dominated by a core technology group, they involve technical innovation throughout the organization driven by a chief executive’s aspirations. 3) visionary customer-driven. The innovations were achieved by implementing a theory of what the customer would need well in the future. Keywords—innovation process; technological change; capability development
Two-photon polymerization technique with sub-50 nm resolution by sub-10 fs laser pulses

Nanofabrication of structures with a feature size of sub-50 nm with ultrashort-laser based two-photon polymerization (2PP) technique is presented. The spatial resolution of the 2PP structures depends on the characteristics of the polymer material and the laser system used for fabrication. Here we compare the successful creation of sub-100 nm structures with two different few-cycle laser systems and chemically modified zirconium-based sol-gel composite material using cross-linker for resolution enhancement.
The effect of inter-layer diffusion on magnetic exchange spring behaviour

The effect of inter-layer diffusion between the magnetically hard and soft layers in magnetic exchange spring systems is examined, using 1D and 2D models. It is shown that diffusion across the hard/soft interfaces leads to an increase in the bending field BB. This increase eventually saturates when the bending field BB and the coercivity BC merge. Moreover, if the increase in the bending field BB is large enough, the nature of the magnetic reversal can be affected. This behaviour is illustrated using a YFe2 dominated YFe2/DyFe2 exchange spring system. In this case the 1D model predicts that inter-layer diffusion can drive a magnetic phase change, from negative to positive coercivity. Discrete 2D model calculations of inter-layer diffusion are also presented and discussed. The latter support the predictions of the 1D model. Finally, while the emphasis is on atomic diffusion, some comments are made concerning interface roughness.
Motion/force control of uncertain acatastatic nonholonomic mechanical systems via sliding modes

The position/force control of Lagrangian mechanical systems with acatastatic nonholonomic constraints is addressed in this paper. The main feature of this paper is that control strategy is developed at the dynamic level and can deal with model uncertainties in the mechanical systems. This is achieved by decomposing the system into two cascaded subsystems: a kinematic system with drift and a lower dimensional system which retains the mechanical system structure. It is shown that the proposed control law guarantees simultaneously the stabilization of the position to an equilibrium point and constraint force tracking in the presence of parameter modeling uncertainties.
Data and text mining Ensemble non-negative matrix factorization methods for clustering protein – protein interactions

Motivation: When working with large-scale protein interaction data, an important analysis task is the assignment of pairs of proteins to groups that correspond to higher order assemblies. Previously a common approach to this problem has been to apply standard hierarchical clustering methods to identify such a groups. Here we propose a new algorithm for aggregating a diverse collection of matrix factorizations to produce a more informative clustering, which takes the form of a ‘soft’ hierarchy of clusters. Results: We apply the proposed Ensemble non-negative matrix factorization (NMF) algorithm to a high-quality assembly of binary protein interactions derived from two proteome-wide studies in yeast. Our experimental evaluation demonstrates that the algorithm lends itself to discovering small localized structures in this data, which correspond to known functional groupings of complexes. In addition, we show that the algorithm also supports the assignment of putative functions for previously uncharacterized proteins, for instance the protein YNR024W, which may be an uncharacterized component of
Optical Afterglows from Cylindrical Jets of Short Gamma-Ray Bursts

Observations of extragalactic radio jets and young stellar jets show that the jets are cylindrical; i.e., they maintain a nearly constant cross section on large scales. It has been suggested that the afterglow behaviors of some long-duration gamma-ray bursts (GRBs) are consistent with the cylindrical jet model of GRBs. Here we study the afterglow emission of cylindrical jets from short-duration GRBs. For the usual conical jet geometry, it is argued that, because of the low fluence of short GRBs, the prospects of detecting the optical afterglow 10 hr after the burst are not promising. However, in the present work we find that if the jets are cylindrical, the chance for detecting the optical afterglow will be increased, even if the burst occurs in a low-density (n ~ 10-3 cm-3) medium. Since the jets are expected to not be well collimated initially and the time when they change from conical to cylindrical is not exactly known, we discuss two cases for the afterglow of cylindrical jets: the jets becoming cylindrical (1) after the gamma-ray-emitting phase and (2) before the gamma-ray-emitting phase. In both cases, the light-curve behaviors, especially the peak time, are sensitive to the cross section radius of the cylindrical jet. In the former case we find that for viewing angles less than ~0.03 rad relative to the jet axis, typical short GRBs have a late-time R-band afterglow with a maximum apparent magnitude of mR ≲ 23, given that the efficiency for producing gamma rays and the shock microphysical parameters of the afterglow are the same in short and long bursts. For the latter case the optical afterglows can always be readily detected with mR < 23 at 10 hr after the burst. Comparison between model light curves and observational upper limits of the optical afterglow flux of a few short GRBs are also made.
Evolution of Clusters of Galaxies

In hierarchical models for structure formation like CDM, the mass scale of clustering evolves rapidly and clusters in the past are predicted to be less massive, but denser and more numerous. The indication from optical searches is that the cluster population is roughly stable in that high velocity dispersion clusters seem to be about as abundant at z ~ 0.5 as at the present while X-ray surveys show a strong negative evolution, there being many fewer highluminosity clusters in the past compared to the present. Using self-similar scaling laws I find that the neutral evolution in the optical agrees quite well with what is expected, but that the negative X-ray evolution is very hard to reconcile with the idea that state of the gas in clusters is the result of gravitational clustering. One way to remedy this discrepancy is to assume that the gas we now see in clusters was heated at some earlier epoch by non-gravitational processes. If one discards the optical observations, an alternative is to invoke primordial fluctuations with a much redder spectrum, and I discuss how one might discriminate between these theories with future observations.
Rao score tests for goodness of fit and independence

SUMMARY Rao's score statistic is a standard tool for carrying out hypothesis tests. A unified approach is given which encompasses many common tests. When a suitable group structure is present, it is shown how the derivation of the test statistic can be simplified. An omnibus test of multivariate normality is derived as an example of group invariance. As another application of Rao score tests, a general method is given for constructing tests of independence.
Particle kinetic equation including weakly turbulent mode coupling

In this article, particle kinetic equations which incorporate the nonlinear wave–particle interaction, as derived in P. H. Yoon [Phys. Plasmas 7, 4858 (2000)] and V. N. Tsytovich [Theory of Turbulent Plasma (Consultants Bureau, New York, 1977), pp. 103–110] are re-examined. A unified formalism is obtained after discrepancies in both references are resolved. The present particle kinetic equation is valid for the velocity space which does not satisfy the linear wave–particle resonance condition, ω−k⋅v≠0, but when the particle velocity of interest primarily satisfies the nonlinear wave–particle resonance, ω−ω′−(k−k′)⋅v=0.