Miracle-dz/UniFAR-FTUs huggingface dataset:
Theoretical and numerical considerations on the surface energy for deformed isotropic nanocrystals

In this paper we start by presenting an analytical analysis to determine the variation in the surface energy of isotropic solids when they are deformed in the elastic domain. This part of our work was based on a recent formulation proposed by Sanfeld and Steinchen and modified for the case of pure solids. We continue our presentation by deducing the form of the surface energy variation by means of molecular dynamics simulations at a finite temperature (300 K). These simulations were performed with single nanocrystals of Al and deformed in the elastic regime along one direction parallel to the surface. These simulations also allowed us to determine the variation in the interplanar spacing of the atomic layers near the surface. Our simulations for the (100), (110) and (111) surfaces exhibit the same multilayer relaxation tendency obtained by other numerical and experimental results.
Confidence Bands for Roc Curves

In this paper we study techniques for generat- ing and evaluating condence bands on ROC curves. ROC curve evaluation is rapidly becoming a commonly used eval- uation metric in machine learning, although evaluating ROC curves has thus far been limited to studying the area under the curve (AUC) or generation of one-dimensional condence intervals by freezing one variable|the false-positive rate, or threshold on the classication scoring function. Researchers in the medical eld have long been using ROC curves and have many well-studied methods for analyzing such curves, includ- ing generating condence intervals as well as simultaneous condence bands. In this paper we introduce these techniques to the machine learning community and show their empirical tness on the Covertype data set|a standard machine learn- ing benchmark from the UCI repository. We show how some of these methods work remarkably well, others are too loose, and that existing machine learning methods for generation of 1-dimensional condence intervals do not translate well to generation of simultanous bands|their bands are too tight.
Greedy optimal homotopy and homology generators

We describe simple greedy algorithms to construct the shortest set of loops that generates either the fundamental group (with a given basepoint) or the first homology group (over any fixed coefficient field) of any oriented 2-manifold. In particular, we show that the shortest set of loops that generate the fundamental group of any oriented combinatorial 2-manifold, with any given basepoint, can be constructed in O(n log n) time using a straightforward application of Dijkstra's shortest path algorithm. This solves an open problem of Colin de Verdière and Lazarus.
A visual model for optimizing the design of image processing algorithms

The paper describes an algorithm for the assessment of image fidelity. The algorithm includes an image processing model of the human visual system for luminance still imagery. The major components of the algorithm are described that model the visual system as three main sensitivity variations. These address the sensitivity as a function of gray level, as a function of spatial frequency, and as a function of image content. To quantify the performance of the algorithm, specific psychophysical experiments were simulated, and these results are shown. <<ETX>>
Structure of Fish Assemblages in Amazonian Rain-Forest Streams: Effects of Habitats and Locality

Abstract We examined fish assemblage structure in three headwater rain-forest streams in the Urubu River Basin, Central Amazonia, as it relates to habitat heterogeneity. Riffles and pools, two types of stream habitat, were defined by current, depth, and substrate parameters, adjusted for Amazonian stream characteristics. We assessed species richness, composition, and abundance as they varied between riffles and pools across three similar streams. Four riffles and four pools were identified in each stream and sampled four times during 1996 and 1997. The samples yielded a total of 856 individuals of 22 species. The most abundant species were in the families Characidae, Lebiasinidae, Helogenidae, and Rivulidae. We found an interactive influence of riffle/pool habitat and stream factors on species richness, composition, and abundance. Rain-forest stream fish assemblages are structured by both habitat and stream locality.
A Knowledge Engineer's Comparison of Three Evidence Aggregation Methods

The comparisons of uncertainty calculi from the last two Uncertainty Workshops have all used theoretical probabilistic accuracy as the sole metric. While mathematical correctness is important, there are other factors which should be considered when developing reasoning systems. These other factors include, among other things, the error in uncertainty measures obtainable for the problem and the effect of this error on the performance of the resulting system.
Optimal and near-optimal advection-diffusion finite-difference schemes. IV. Spatial non–uniformity

For the non-constant-coefficient advection-diffusion equation with decay a(∂tc + λc + u∂sc) - ∂s(aκ∂sc) = q, the non-uniformity can almost be removed with a local change of variables from c(s,t) to b(x,t). So, in numerical computations non-uniformity need not imply any reduction from optimal accuracy. A computational grid that was uniformly spaced with respect to s becomes non-uniform with respect to the intrinsic x-coordinate. Suitable non-uniform grid, optimal and near-optimal compact finite-difference schemes were derived in part II of this sequence of papers. The cylindrical advection-diffusion equation is used as an exactly solvable test case.
Reordering constraints for pthread-style locks

C or C++ programs relying on the pthreads interface for concurrency are required to use a specified set of functions to avoid data races, and to ensure memory visibility across threads. Although the detailed rules are not completely, it is not hard to refine them to a simple set of clear and uncontroversial rules for at least a subset of the C language that excludes structures (and hence bit-fields). We precisely address the question of how locks in this subset must be implemented, and particularly when other memory operations can be reordered with respect to locks. This impacts the memory fences required in lock implementations, and hence has significant performance impact. Along the way, we show that a significant class of common compiler transformations are actually safe in the presence of pthreads, something which appears to have received minimal attention in the past. We show that, surprisingly to us, the reordering constraints are not symmetric for the lock and unlock operations. In particular, it is not always safe to move memory operations into a locked region by delaying them past a pthread_mutex_lock() call, but it is safe to move them into such a region by advancing them to before a pthread_mutex_unlock() call. We believe that this was not previously recognized, and there is evidence that it is under-appreciated among implementors of thread libraries. Although our precise arguments are expressed in terms of statement reordering within a small subset language, we believe that our results capture the situation for a full C/C++ implementation. We also argue that our results are insensitive to the details of our literal (and reasonable, though possibly unintended) interpretation of the pthread standard. We believe that they accurately reflect hardware memory ordering constraints in addition to compiler constraints. And they appear to have implications beyond pthread environments.
Evaluation of mobile ARM-based SoCs for high performance computing

The electrical power consumption of current supercomputers has become the key limiting factor to successfully reach exascale. To further increase energy efficiency, the use of mobile system-on-chips (SoCs) has been proposed in the past. In this work we investigate four development boards equipped with different SoCs with respect to their suitability for HPC. Each of the boards is carefully benchmarked for high floating point computing performance, high memory bandwidth, low latencies, and power consumption, all of which we identified as key properties for successful HPC systems. In contrast to earlier work, we also include OpenCL-capable graphics processing units integrated in the SoC in our benchmarks. Our benchmark results show that mobile SoCs are not ready for a successful adoption in HPC yet. While theoretical peak compute performance and memory bandwidth suggest SoCs to be a competitive with existing HPC systems, practical values are most of the time much lower. Therefore, none of the SoCs provides an attractive option for HPC in terms of lower acquisition costs or higher energy efficiency.
Gesture recognition based on depth difference distribution

We present a novel motion descriptor for gesture recognition based on depth camera. Since each object motion leads to a specific depth change characterized by depth difference, we can recognize object motion via Depth Difference Distribution (DDD) in object region. The DDD is approximated by DDD descriptor in three steps. First, each pixel's depth difference value is quantified into Depth Difference (DD) codes. Second, the object region is separate into several sub-regions. Third, in each sub-region, a vector is generated to describe the distribution of each DD code. The vectors of each DD code in each sub-region are cascaded into the final DDD descriptor to approximate the depth difference distribution caused by object motion. DDD descriptor is a combination of both motion and shape information. Experiment shows a robust gesture detection performance is achieved within large distance and view angle variation range.
Reducing interrater variability and improving health care: a meta-analytical review.

OBJECTIVES In the scientific literature about reliability, the main approach to increasing reliability seems to involve increasing the number of observers and improving the instrument used. Other aspects for improving reliability - like the training of raters - seem to receive less notice. It is worth asking whether this technical approach could be complemented by training the user of the instrument. A systematic meta-analytical review of the research literature was performed to answer this question and examine the effectiveness of planned interventions for improving interrater reliability of health care professionals. METHOD The databases of PubMed (MEDLINE), Embase, Omega and PsycINFO were searched. The inclusion criteria were met by 57 studies. Details extracted from the studies included the study design, the number of observers and the number of observed cases, the intervention, the type of instrument (whether or not it was highly technical), and statistical information about the agreement before and after the intervention. Interventions were categorized into three groups: training of professionals, improving the diagnostic instrument and a combination of training and improving the instrument. A meta-analysis was performed by means of linear regression. RESULTS The interventions were arranged according to their effectiveness in improving the diagnostic instrument (mean change: β = 0.13), training combined with improving the instrument (mean change: β = 0.10) and training (mean change: β = 0.09). CONCLUSION On average, although all types of interventions are effective, improving the diagnostic instrument seems to be the most effective. Especially when highly technical instruments were concerned, improvement proved to be very effective (β = 0.52). Because instrumental variables constitute a major source of error, improving the instrument is an important approach. However, this review offers solid arguments that can complement the literature and practice, with a focus on training the user of the instrument.
Electrospinning fabrication, structural and mechanical characterization of rod-like virus-based composite nanofibers

Tobacco mosaic virus (TMV) was electrospun with polyvinyl alcohol (PVA) into continuous TMV–PVA composite nanofibers to form a biodegradable nonwoven fibrous mat as an extracellular matrix (ECM) mimetic. Morphological characterizations by electron microscopy showed that the addition of varying amounts of TMV resulted in homogeneous nanofibers without phase separation and did not change the diameter of the composite nanofibers. The orientation of TMV in as-spun fibers could be readily controlled and post-processing of the nonwoven TMV–PVA mat significantly improved its water resistance. In addition, tensile tests were performed on individual nanofibers, which revealed that the TMV–PVA composite nanofibers achieved a comparable Young's modulus as PVA nanofibers. Since the modification of TMV is readily achieved via genetic or chemical methods, this process offers a facile way to incorporate a variety of functionalities into polymer nanofibers. As a demonstration of its potential as ECM mimetic, a mutant TMV containing RGD peptide was co-spun with PVA and the resulting fibrous substrates were used to promote cell growth.
Thermal rheological analysis of cure process of epoxy prepreg

The cure process of epoxy prepreg used as composite pipe joints was studied by means of differential scanning calorimetry (DSC), Bohlin Rheometer and other techniques. Isothermal DSC measurements were conducted between 110 and 220 C, at 10 C intervals. The results show that the complete cure reaction could be achieved at 220 C. The isothermal cure process was simulated with the four-parameter autocatalytic model. Except in the late stage of cure reaction, the model agrees well with the experimental data, especially at high temperatures. To account for the effect of diffusion on the cure rate, a diffusion factor was introduced into the model. The modified model greatly improved the predicated data at the late stage of cure reaction. The dynamic cure process was different from the isothermal cure process in that it is composed of two cure reactions. For dynamic cure process, a three-parameter autocatalytic model was used. The parameters in the model were determined by two methods. One was based on Kissinger and Ozawa approach. The whole curing process was modeled with two reactions. Another method was based on Borchardt and Daniels kinetic approach with the whole curing process modeled with one reaction. The fitted results by the first and second methods agreed well with the experimental values in the late and early cure stages, respectively. Rheological properties of epoxy prepreg are closely related to the cure process. With the development of the cure reaction, gelation occurs and epoxy prepreg becomes difficult to process. As the temperature increases, the gel time decreases. Viscosity profiles were described by different models. Except for the first and nth order viscosity
Component design-based model for deformation and rupture of tough fibre-reinforced ceramic matrix composites

A model is developed for the deformation and fracture of tough fibre-reinforced ceramic matrix composites for use in component design. The model is based on a single continuum damage state parameter given by the ratio of the number of failed to unfailed fibres. The composite is assumed to be instantaneously elastic and the stress-strain response is determined from the stress-damage history. The model includes the effects of debonding and fibre pull-out, through weakest fibre Weibull statistics, and estimates of composite ductility have been made. The model quantitatively describes the dominant mechanism of deformation and fracture, and in the following paper, it is shown how the model may be used in component design.
A New Approach to Percutaneous Subclavian Venipuncture to Avoid Lead Fracture or Central Venous Catheter Occlusion

Pacemaker and defibrillator leads and central venous catheters placed by commonly recommended techniques have been found to pass through the subclavius muscle, the costocaracoid ligament, or the costoclavicular ligament before entering veins medial to the first rib. Entrapment by these soft tissues subjects leads and catheters to stresses imposed by movements of the ipsilateral upper extremity. Accordingly, a new approach has been developed that introduces the lead or catheter into the subciavian vein near the lateral border of the first rib. This placement avoids soft tissue entrapment and may extend the longevity of leads and catheters.
Jthread, a deadlock-free mutex library

We design a mutex library for Hop -- a dialect of Scheme which supports preemptive multithreading and shared memory -- that mixes deadlock prevention and deadlock avoidance to provide an easy to use, expressive, and safe locking function. This requires an operation to acquire several mutexes simultaneously, for which we provide a starvation-free algorithm. Choosing a formal definition of starvation-freedom leads us to identify the concept of asymptotic deadlock. Preliminary observations seem to show that our library has negligible impact on the performance of real-life applications. Our work could be applied to other languages such as Java.
Analytical Model for Thermal Warpage History of Laminated PBGAs

Thermally induced warpage can lead to deformed or bridged solder joints during reflow of large laminate-based area-array components like high I/O PBGAs. This study presents a simple, rapid-assessment modeling capability to assess the warpage risk of such components, based on their architecture information. A piece-wise, classical laminated plate model is used in this study for estimation of the thermally induced warpage. This model uses temperature-dependent elastic properties to account for the large change in material behavior as the reflow temperature exceeds the glass-transition temperatures of the various polymers (substrate, die attach and epoxy molding compound). The laminated plate modeling strategy provides the capability to handle complex component architectures and temperature gradients in the thickness direction. The piecewise modeling strategy allows the model to account for the changes in the stack-up as we move from under the die footprint to the region outside the footprint. Several test cases are examined during the model development. Results are compared to detailed finite element models, as well as to other analytical methods like finite-length plate models. The model is found to be very sensitive to the thermo-mechanical properties of common epoxy molding compounds (EMCs) above their glass transition temperature. Since the model approximates a complex viscoplastic problem with an equivalent temperature-dependent elastic formulation, part of the focus is on developing equivalent temperature-dependent material properties to calibrate the model. The goal in this approximation is to find a suitably smooth transition between the material properties below and above Tg , based on the discrete properties typically found in data sheets. The trends predicted by this simplified model are also found to agree well with shadow moire measurements of warpage in actual components during large temperature excursions.Copyright © 2008 by ASME
Frequency-Modulated Interrupted Continuous Wave as Wall Removal Technique in Through-the-Wall Imaging

Undesired wall reflections in through-the-wall imaging can mask the return from actual targets and saturate and block the receiver. We propose frequency-modulated interrupted continuous wave (FMICW) signals as a novel wall removal technique and validate its effectiveness through numerical simulations and experiments performed using a radar system built for the purpose. FMICW waveforms appear to mitigate wall reflections and benefit the through-wall detection of stationary targets and of people moving or breathing behind different kinds of wall.
LETTER TO THE EDITOR: Scalar fields as dark matter in spiral galaxies

We present a model for the dark matter in spiral galaxies, which is a result of a static and axial symmetric exact solution of the Einstein-dilaton theory. We suppose that dark matter is a scalar field endowed with a scalar potential. We obtain that (a) the effective energy density goes like 1/(r 2 +rc 2 ) and (b) the resulting circular velocity profile of test particles is in good agreement with the observed one.
Methylation detection oligonucleotide microarray analysis: a high-resolution method for detection of CpG island methylation

Methylation of CpG islands associated with genes can affect the expression of the proximal gene, and methylation of non-associated CpG islands correlates to genomic instability. This epigenetic modification has been shown to be important in many pathologies, from development and disease to cancer. We report the development of a novel high-resolution microarray that detects the methylation status of over 25 000 CpG islands in the human genome. Experiments were performed to demonstrate low system noise in the methodology and that the array probes have a high signal to noise ratio. Methylation measurements between different cell lines were validated demonstrating the accuracy of measurement. We then identified alterations in CpG islands, both those associated with gene promoters, as well as non-promoter-associated islands in a set of breast and ovarian tumors. We demonstrate that this methodology accurately identifies methylation profiles in cancer and in principle it can differentiate any CpG methylation alterations and can be adapted to analyze other species.
KOF Working Papers

We empirically analyze convergence of European producer and consumer prices for diesel fuel and investigate the role of excise taxation. By comparing the speed of convergence of prices and taxes we find a surprisingly fast speed of convergence for consumer prices. While this can in part be explained by fuel tourism, the main driving force is producer price dynamics. Tax convergence contributes weakly to price convergence, but the overall effect is to slow down consumer relative to producer price convergence.
System-Level Modeling for Transient Electrostatic Discharge Simulation

This paper introduces an improved electrostatic discharge (ESD) system-level transient simulation modeling method and discusses its validation using IEC 61000-4-2 ESD pulses on a real-world product. The system model is composed of high current and broadband (up to 3 GHz) models of R, L, C, ferrite beads, diodes, and integrated circuit IO pins. A complex return path model is the key to correctly model the system's response to the IEC excitation. The model includes energy-limited time-dependent IC damage models. A power-time integral method is introduced to accurately determine if a junction would experience thermal runaway under an arbitrary injection waveform. The proposed method does not require knowledge of the junction's microscopic geometry, material information, defect location, or melting temperature.