Miracle-dz/UniFAR-FTUs huggingface dataset:
Monte-Carlo Sensitivity Analysis for Controlled Direct Effects Using Marginal Structural Models in the Presence of Confounded Mediators

In randomized trials, investigators are frequently interested in estimating the direct effect of a treatment on an outcome that is not relayed by intermediate variables, in addition to the usual intention-to-treat (ITT) effect. Even if the ITT effect is not confounded due to randomization, the direct effect is not identified when unmeasured variables affect the intermediate and outcome variables. Although the unmeasured variables cannot be adjusted for in the models, it is still important to evaluate the potential bias of these variables quantitatively. This article proposes a sensitivity analysis method for controlled direct effects using a marginal structural model that is an extension of the sensitivity analysis method of unmeasured confounding introduced in the context of observational studies. The proposed method is illustrated using a randomized trial of depression.
Point-contact sensors: New prospects for a nanoscale-sensitive technique

Point contacts have been discovered to present excellent and unprecedented characteristics when used as gas sensors. A novel concept has been tested successfully and opens the way to useful applications. Copper point contacts were investigated in gas media such as NOx, HCl, H2S and human breath. They reveal high sensitivity to these gases: the measured signal increases by 2-3 orders of magnitude upon gas exposure. Sensor parameters are fully restored when gas action ceases. Stable reproducibility of experimental results was observed after several exposure cycles onto the investigated point contacts.
Diabatic sources of potential vorticity in the general circulation

Abstract A form of the potential vorticity (PV) budget is proposed that facilitates analysis on the role of global heat sources and sinks in the general circulation. A local diabatic source of PV occurs due to vertical variations of heating. Additionally, since the irrotational mass circulation in isentropic coordinates is uniquely linked to diabatic heating, the associated horizontal advection of PV may be viewed as a diabatic source. The sum of these processes constitutes an effective “baroclinic wave source” due to diabatic processes, and is analogous to the effective barotropic Rossby wave source due to divergence as discussed by Sardeshmukh and Hoskins. Diagnostic results are presented for the upper-tropospheric PV balance at 350 K during northern winter. When the PV budget is diagnosed in its conventional form, the midlatitude flow appears insulated from the influence of tropical heating in the sense that diabatic sources and sinks are mainly due to vertical variations of extratropical heat sources .
Parachute Strain and Deformation Measurements using Imaging and Polymer Strain Sensors

(Abstract) The purpose of this paper is to present experimental results obtained by using both contacting and non-contacting measurements on parachute fabric. Contacting measurements were made using a novel polymer high strain sensor, Metal Rubber™. The equipment that is used to acquire non-contacting measurements is a three-dimensional (3D) image correlation system (Aramis 3D HR/RS System). Four experiments were conducted including a parachute fabric tensile test, a biaxially loaded cylinder test, a parachute airbag test, and an inverted water-filled parachute test. Contacting measurements are compared to the strain measured by a set of optical imaging cameras during the high strain tensile test of the parachute fabric. The results indicate that the imaging system can provide useful strain and deformation measurements for parachute fabric and that the polymer sensor can be used to measure strain. I. Introduction he continuing necessity for strategic mobility and reliance on airborne insertion requires the Army's focus to be centered on soldiers' protection during these tactics. In Operation Just Cause, 50% of combat injuries in the first 24 hours were jump related. In addition, parachuting is one of the highest training-related injury producers in the Army. Increasingly heavy payloads are compounding the risks and new equipment needs to be implemented to ensure the soldiers' safety. Prior to active field-testing of alternative parachute designs, the void of detailed, validated, physics-based, High Performance Computer (HPC) Modeling needs to be filled. The experimental tools necessary for full model validation and understanding the detailed physics of any parachute system were not available until now. Within this study, contacting and non-contacting methods of measurement are employed to obtain strain and deformation data, which can be used to validate the unproven structural finite element and computational fluid dynamic codes recently developed at the Army's Natick Soldier Research, Development, and Engineering Center (NSRDE) and other universities. The contacting measurements are made using a Metal Rubber™ sensor. Metal Rubber™, a material developed by Nanosonic, Inc., is a unique self-assembled nanocomposite material that combines the high electrical conductivity of metals with the low mechanical modulus of elastomers. Due to its relatively low modulus of elasticity, the Metal Rubber™ sensor will not mechanically affect the strain and displacement of the parachute fabric. These sensors operate in the same manner as a conventional metal foil strain gage, such that a change in length of the sensor will produce a change in resistance. Since these Metal Rubber™ sensors have only recently been developed, their use in the measurement of fabric strain has been previously unexplored. Furthermore, several challenges have been presented concerning these sensors. These challenges include attaching leads to the surface of the sensor and adhering the sensors to the fabric. T
Calibration as estimation

One aspect of calibration in macroeconomics is the notion that free parameters of models should be chosen by matching certain moments of the simulated models with those of actual data. We formally examine this notion by treating the process of calibration as an econometric estimator. A numerical version of the Mehra-Prescott (1985) economy is the setting for an evaluation of calibration estimators via Monte Carlo methods. While these estimators sometimes have reasonable finite-sample properties they are not robust to mistakes in setting non-free parameters. In contrast, generalized method of moments (GMM) estimators have satisfactory finite-sample properties, quick convergence, and informational requirements less stringent than those of consistent calibration estimators. In dynamic equilibrium models in which GMM is infeasible we offer some suggestion for improving estimates based on calibration methodology.
Middle atmospheric winds and tides over London, Canada (43°N, 81°W) during 1992–1993

Mean winds and tides have been measured with the new MF radar at London, Ontario. Using a 1-year continuous set of data, the mean winds are compared with a recent empirical model. The diurnal and semidiurnal tides are discussed, and these are compared with results from other similar midlatitude ground-based radars. There are interesting similarities and discrepancies, although we note that some of the initial comparisons use data from different years. The diurnal and semidiurnal tides are also compared with recent tidal models. Tidal characteristics are generally consistent with the models, but again some differences are also noted.
Systems of difference equations with general homogeneous boundary conditions

Strang has discussed stability of difference equations whose solutions satisfy the special boundary condition u=O on and outside of the boundaries. We shall use Toeplitz matrices to generalize this theory to systems of equations in one space variable with arbitrary homogeneous boundary conditions. The discussion will be confined to problems in the quarter plane with constant coefficients. The results can be easily generalized to variable coefficient and two point boundary value problems, using Kreiss' method [1] and/or Strang's in [2] and [3]. We shall derive Kreiss' sufficient conditions for stability of dissipative hyperbolic systems with constant coefficients as a corollary to a more general result. In particular, the condition of dissipativity is replaced by a weaker condition. We treat the explicit case in the main part of this work and add the implicit case as an appendix in part 7. The main results are stated in XIX and XXVIII. Kreiss' Theorem is derived in XXII. We give nondissipative examples in XXIII and XXIX. We hope to extend this technique to include problems in several space variables in the near future.
The Strategy and Its Impact on the Use of Decision Support Systems in Palestinian Universities

: Research Objective: The aim of the research is to identify the strategy and its impact on the use of decision support systems in universities. Research Community and Sample: The research was applied to Islamic University- Gaza, and the academic research sample with an administrative position, which was 87 employees. Research Methodology: A descriptive and analytical approach was used and secondary data was obtained through a questionnaire that was distributed to the research community using the comprehensive enumeration method. The questionnaire was distributed to all members of the study population, and 65 questionnaires were retrieved with a recovery rate of 79.3% Research Results: The research concluded with a set of results, the most important of which are:
A finiteness lemma, brauer's theorem and other iIrreducibility results

A technical lemma is proved for certain semigroups of matrices. It has several applications to problems concerning irreducible semigroups satisfying spectral conditions, e.g., submultiplicativity of spectrum. It is also used to give extensions of the following theorem of Brauer's. If U is a finite group of complex matrices, so that for some integer m, every U in U, satisties Um =I then U has a representation over the cyclotomic field Q(ω), where ω is a primitive m-th root of unity.
Jaguar: A high-performance quantum chemistry software program with strengths in life and materials sciences

Jaguar is an ab initio quantum chemical program that specializes in fast electronic structure predictions for molecular systems of medium and large size. Jaguar focuses on computational methods with reasonable computational scaling with the size of the system, such as density functional theory (DFT) and local second-order Moller–Plesset perturbation theory. The favorable scaling of the methods and the high efficiency of the program make it possible to conduct routine computations involving several thousand molecular orbitals. This performance is achieved through a utilization of the pseudospectral approximation and several levels of parallelization. The speed advantages are beneficial for applying Jaguar in biomolecular computational modeling. Additionally, owing to its superior wave function guess for transition-metal-containing systems, Jaguar finds applications in inorganic and bioinorganic chemistry. The emphasis on larger systems and transition metal elements paves the way toward developing Jaguar for its use in materials science modeling. The article describes the historical and new features of Jaguar, such as improved parallelization of many modules, innovations in ab initio pKa prediction, and new semiempirical corrections for nondynamic correlation errors in DFT. Jaguar applications in drug discovery, materials science, force field parameterization, and other areas of computational research are reviewed. Timing benchmarks and other results obtained from the most recent Jaguar code are provided. The article concludes with a discussion of challenges and directions for future development of the program. © 2013 Wiley Periodicals, Inc.
Viscosity of Liquid Helium II near the Lambda Point

The theory of Landau and Khalatnikov for the viscosity of liquid He II is examined in the neighbourhood of the lambda point. Arguments are advanced against the validity of the ideal gas approximation for rotons, and a qualitative roton liquid model is proposed. The temperature dependence of viscosity of the liquid model is found to correspond to the observed viscosity above 1-8°k, and with the discontinuity in the temperature derivative of viscosity at the lambda point.
Phonetic differences in glottalic consonants

Data on glottalic consonants in a number of languages were examined. Data on implosives come from Hausa, Degema, and three Eastern Ijo languages, all spoken in Nigeria. Ejective data come from Hausa and Navaho. The implosives in Degema and the Ijo languages show a strong positive correlation (r = 0.9; p = 0.025) between the closure duration and the intensity of implosion. However, Hausa implosives do not follow this correlation in that they have a high intensity implosion with a relatively brief closure duration. This is attributed to the fact that Hausa implosives are also laryngealized, and the resulting lower airflow into the vocal tract makes it possible to have a more efficient implosion in Hausa. Due to the different phonation type the implosive mechanism is thus considerably different in Hausa than in the other languages. The ejectives in Hausa and Navaho differed along several parameters: total duration, ratio closure duration/open interval, and phonation type in the vowel onset. Thus what appears to be the same sound nevertheless has to be described in different ways for different languages. [This work was supported by NSF. ]
A view-time based potential field method for moving obstacle avoidance

This paper proposes a new motion planning method of a mobile robot avoiding moving obstacles. We use an artificial potential field method and the view-time concept. The view-time is defined as the period between one sampling time to the next. It is assumed that the position and the velocity of obstacles are monitored at each sampling time. From the position and velocity at sampling time, we calculate the probability density of the obstacle trajectory for a view-time, based on the assumption that the obstacle motion is being modeled as a random walk process. The probability that the position can be swept by an obstacle during a view-time is calculated from the probability density function of the obstacle trajectory. Then artificial potential is assigned at every position by considering the probability of obstacle trajectory. The force induced by the artificial potential field repels the robot away from the probable obstacle trajectory. This method is a look ahead scheme and is effective for moving obstacle avoidance.
Design of instantaneous field of view of the rosette scanning infrared seeker and dynamic simulation

A rosette scanning IR seeker is the device mounted on the IR guided missile. It offers the positions and images of target to missiles' servo system by scanning a total field of view (TFOV) in a rosette pattern with a single detector. An instantaneous field of view (IFOV) is a diameter of the detector moving along the path of the rosette pattern. The IFOV has the property that its smaller size provides the less interference of background signals and detector noise. If its size is too small to cover the TFOV, however, it produces the invisible regions in the TFOV and decreases the performance of the seeker. For full scan coverage, it is necessary to design the small IFOV without the invisible regions as possible. In this paper, we propose a new method to design the smaller IFOV than the conventional one. The IFOV of the proposed method is defined as a distance between two points, which are selected among the intersected points between any petal and its neighbors. By comparing a noise equivalent flux density of the proposed method with that of the conventional, we confirm that the former is better than the latter in terms of performance. To evaluate the designed IFOV dynamically, we simulate the rosette scanning IR seeker using MATLAB-SIMULINK.
Forward Displacement Analysis of Non-Plane Two Coupled Degree Nine-Link Barranov Truss Based on Hyper-Chaotic Newton Downhill Method

The hyper-chaotic Newton downhill method finding all real solutions of nonlinear equations was proposed and the forward displacement analysis on the 33th non-plane 2-coupled–degree nine-link Barranov truss was completed. Four constrained equations were established by vector method with complex numbers according to four loops of the mechanism and four supplement equations were also established by increasing four variables and the relation of sine and cosine function. The established eight equations are that of forward displacement analysis of the mechanism. Combining Newton downhill method with hyper-chaotic sequences, hyper-chaotic Newton-downhill method based on utilizing hyper-chaotic discrete system to obtain locate initial points to find all real solutions of the nonlinear questions was proposed. The numerical example was given. Comparison was also done with other finding solution method. The result shows that all real solutions have been quickly obtained, and it proves the correctness and validity of the proposed method.
A Method for Determining Tissue Conductivity and Thickness in Stratified Biological Structure

A simple method is proposed for determining the tissue conductivity and layer thickness in a stratified biological structure. Under illumination of a horizontal coil above the biological structure, a secondary magnetic field is generated, which results in a change of impedance of the coil. From the measured change of the coil impedance, the conductivity of tissue of interest and the layer thickness can be determined by an inverse calculation. To explore the feasibility of the proposed method, a numerical simulation for the measurement and an inverse computational technique, based on an improved genetic algorithm, are developed and presented.
Exchange-induced charge inhomogeneities in rippled neutral graphene

A mechanism that induces charge density variations in corrugated graphene is proposed. Here it is shown how the interplay between lattice deformations and exchange interactions can induce charge separation, i.e., puddles of electrons and holes, for realistic deformation values of the graphene sheet. The induced charge density lies in the range of 10 11 –1 0 12 cm �2 , which is compatible with recent measurements.
An evaluation of the long‐wave radiative transfer code used in the Met Office Unified Model

A detailed evaluation of the radiative transfer code used in the Met Office Unified Climate/Forecast Model is performed, comparing it with a line‐by‐line model and testing the climatic effects of errors in a radiative‐‐convective model. The radiative forcing at the tropopause due to CO2 changes within SRES scenarios and across Quaternary glacial cycles is represented with reasonable accuracy, suggesting that surface temperature will be correctly predicted. However, this is achieved by partial cancellation of opposing errors in upward and downward fluxes. The changes in the vertical profiles of radiative fluxes and the changes to surface and top‐of‐atmosphere fluxes all show significant errors, even at twice pre‐industrial CO2. This causes a sign error in the change in the convective flux in the radiative‐‐convective model. Performance of the code deteriorates rapidly above four times pre‐industrial CO2. For less‐abundant greenhouse gases, CH4 and N2O, the errors are larger as a proportion of their radiative forcings. Errors for surface and top‐of‐atmosphere fluxes for CO2 are similar to those from the mean of the general circulation model (GCM) codes submitted to the intercomparison of radiation codes for IPCC AR4, implying that errors as found here may not be uncommon in climate models. A renewed emphasis on accuracy in radiative transfer calculations and openness in intercomparison studies is necessary to improve the modelling of climate change. Copyright © 2009 Royal Meteorological Society
The Effect of Error Correlation on Interfactor Correlation in Psychometric Measurement

This article shows how interfactor correlation is affected by error correlations. Theoretical and practical justifications for error correlations are given, and a new equivalence class of models is presented to explain the relationship between interfactor correlation and error correlations. The class allows simple, parsimonious modeling of error correlations via prespecifying reliabilities. Within the class, the correlation between latent factors can be as high as 1.0, and as low as the correlation between certain component scores. The models are indistinguishable in terms of parameter parsimony, identifiability, and fit statistics, implying that interfactor correlation is not identifiable within the class. The existence of the class is problematic for psychometric measurement, because estimates of interfactor correlation form the foundation of much of the literature.
Fractals and ultrasmooth microeffects

In this paper, a portion of the nonstandard methods first introduced by Nottale and Schneider [J. Math. Phys. 25, 1296 (1984)] for the investigation of fractal behavior are replaced by methods employing polysaturated enlargements. This process yields internal functions that are ultrasmooth and have a standard part equal to the original fractal. These ultrasmooth nonstandard functions also possess a well‐behaved * integral length concept. Additionally, a method is presented that shows that if certain behavior is modeled after a simple finitely discontinuous step function, then this function is also the standard part of an internal hypersmooth nonstandard approximation.
The importance of the forces acting on particles in turbulent flows

The analysis of the importance of the forces that act over an ensemble of particles in a turbulent field has been carried out by using direct numerical simulation for a wide range of density ratios (2.65<ρ<2650). It has been observed that, compared to the Stokes drag, the added mass is always negligible, the pressure drag is relevant for density ratios O(1), and the Basset force is appreciable for the whole range investigated. However, the effect of these forces on the particle dispersion is about 1% for ρ∼1 as well as for large density ratios.
Tomographic reconstructions from incomplete data-numerical inversion of the exterior Radon transform

X-rays passing through the beating heart or bone can create error in standard computer tomographic scans of the organs around these regions. Often doctors are interested in imaging only the organs surrounded in these regions, not the regions themselves. The author's algorithm reconstructs the organs around the heart or metal without using the X-rays that create the error. Reconstructions of mathematical phantoms using this algorithm are given, and a description of the completed algorithm is presented. A mathematical explanation is given for the difficulties inherent in any tomography problem with incomplete data. It predicts weaknesses inherent in all reconstruction algorithms that use incomplete data.
Stochastic modelling of model errors: a simulation study

In the setting with known ‘truth’, the spatio‐temporal structure of forecast‐model (tendency) errors is studied. The shallow‐water model is used as the ‘truth’ and the vorticity equation as a forecast model. It is found that state‐dependent model errors (MEs) are of primary importance. The residual state‐independent (stochastic) part of MEs can be modelled with the advection‐diffusion equation driven by the white noise. The ME effective advection velocity appears to be very different from the wind and resembles the Rossby‐wave phase velocity. Three versions of increasing complexity for the advection and diffusion operators are proposed. Ensemble‐based adequacy checks of the proposed ME model are presented. Sensitivity of the ensemble forecast‐error spatial and temporal structure to various aspects of the ME model used to create the ensemble is investigated. Copyright © 2005 Royal Meteorological Society