Miracle-dz/UniFAR-FTUs huggingface dataset:
A Novel Detector Geometry for X-Ray CT

State-of-the-art X-ray computed tomography (CT) scanners all employ the conventional detector geometry which forms an arc concentric to the X-ray source. While each collected projection forms an equiangular dataset, the distance of each projection sample to the iso-center is nonuniformly spaced. During the cone-beam to parallel-beam conversion, both channel-wise and view-wise rebinning are required, leading to a degraded spatial resolution and an increased aliasing artifact. In this article, we propose a novel detector geometry that acquires evenly spaced projection samples relative to the iso-center and only view-wise rebinning is required to form a parallel dataset. To ensure that the detector cell size is independent of the cell position, the source-to-detector distance varies as a function of the detector fan-angle. Each detector module is tilted to guarantee the orthogonality of the detector surface to the X-ray. Extensive computer simulations were performed to demonstrate the efficacy of our design. Spatial resolution was measured with the modulation transfer function (MTF) and the proposed design offers a 12.6% improvement. When the equiangular configuration was retuned to match the spatial resolution, the proposed design exhibits an 8.8% noise reduction. In addition, aliasing artifacts were significantly reduced at locations away from the iso-center.
Vibration and Position Tracking Control of a Flexible Beam Using SMA Wire Actuators

This paper presents vibration and position control of a flexible beam structure by adopting shape memory alloy (SMA) wire actuators. The governing equation of motion of the proposed flexible structure is obtained via Hamilton's principle. The dynamic characteristics of the SMA wire actuator are experimentally identified and incorporated with the governing equation to furnish a control system model in the state space. Subsequently, a sliding mode controller which has inherent robustness to external disturbances and parameter uncertainties is formulated. The controller is then empirically realized for vibration control with relatively large tip displacement. In addition, tip position tracking control to follow desired trajectories with low-frequency sine and square waves is undertaken. Control performances such as tracking error are evaluated through both computer simulation and experimental investigation in time domain.
Pulse number dependence of laser-induced periodic surface structures for femtosecond laser irradiation of silicon

The formation of nearly wavelength-sized laser-induced periodic surface structures (LIPSS) on single-crystalline silicon upon irradiation with single (N=1) and multiple (N≤1000) linearly polarized femtosecond (fs) laser pulses (pulse duration τ=130 fs, central wavelength λ=800 nm) in air is studied experimentally. Scanning electron microscopy (SEM) and optical microscopy are used for imaging of the ablated surface morphologies, both revealing LIPSS with periodicities close to the laser wavelength and an orientation always perpendicular to the polarization of the fs-laser beam. It is experimentally demonstrated that these LIPSS can be formed in silicon upon irradiation by single fs-laser pulses—a result that is additionally supported by a recent theoretical model. Two-dimensional Fourier transforms of the SEM images allow the detailed analysis of the distribution of the spatial frequencies of the LIPSS and indicate, at a fixed peak fluence, a monotonous decrease in their mean spatial period between ∼770 nm.
In solid localization of finger impacts using acoustic time-reversal process

Time reversal in acoustics is a very efficient solution to focus sound back to its source in a wide range of materials including reverberating media. It expresses the following properties: A wave still has the memory of its source location. The concept presented in this letter first consists in detecting the acoustic waves in solid objects generated by a slight finger knock. In a second step, the information related to the source location is extracted from a simulated time reversal experiment in the computer. Then, an action (turn on the light or a compact disk player, for example) is associated with each location. Thus, the whole system transforms solid objects into interactive interfaces. Compared to the existing acoustic techniques, it presents the great advantage of being simple and easily applicable to inhomogeneous objects whatever their shapes. The number of possible touch locations at the surface of objects is shown to be directly related to the mean wavelength of the detected acoustic wave.
Sosyal Sermaye ve Özümseme Kapasitesi İlişkisi: Kocaeli Örneği

In order not to lose their customers and to gain new customers under the pressure of the competitive environment, firms strive to gain an advantage over their competitors by innovating. Innovation efforts of firms are affected by the information resources they hold. In this direction, firms traditionally use the knowledge bases they have created through Research and Development (R&D) activities. However, firms also need information located outside their borders. Firms serach for the information they need outside their borders, find the appropriate one, transfer it into thier inside of the firm and apply it to their products or services, providing economic benefits. The ability of firms to transfer external information to their products constitutes their absorptive capacity. On the other hand, the social capital of a firm provides access to some resources. In this study, the effect of the social capital of the firms, in particular the external social capital outside the boundaries of the firm, on the firms’ absorptive capacity. In this context, as a result of the analysis conducted by using the structural questionnaire and the data obtained from 112 enterprises registered to Kocaeli and the Chamber of Industry, it has been determined that the social capital, in particular external social capital developed by firms’ relations with other actors has a positive effect on the information absorptive capacity. Keywords: Social Capital, External Social Capital, Absorptive Capacity
Variability and Predictability in an Empirically Forced Global Model

Abstract Climatological and predictability features of a simplified moist general circulation model are described herein. The simplified model is driven by empirical forcings designed to eliminate systematic errors and maintain computational efficiency. Resulting perpetual January climatological features of forced variables such as the tropospheric heights and rotational winds, as well as unforced variables such as the velocity potential, compare well with the observations. Unforced temporal variations in the midlatitude 500-mb geopotential, as well as the tropical circulation's intraseasonal oscillation, are also simulated reasonably well. Short-range persistence and predictability features of this model replicate geographical persistence and predictability features from simpler models and from numerical weather prediction. The streamfunction is highly persistent in the extratropics, less so in the tropical regions; similarly, the streamfunction is predicted better in midlatitude regions than in the trop.
Impulsive control strategy for a chemostat model with nutrient recycling and distributed time‐delay

On the basis of the simplest and deterministic chemostat model, we introduce impulsive input, nutrient recycling, and distributed time‐delay into the model in this paper. By using comparison theorem, Floquet theory, and small amplitude skills in the impulsive differential equation, it proves that if the period of impulsive input is too long and the parameter α of the kernel function in the delay is too small, then there exists a microorganism‐eradication periodic solution that is globally asymptotically stable, and the cultivation of the microorganism fails. On the contrary, if we choose suitable impulsive strategy, such as increasing the concentration of the substrate or enhance the proportion of the concentration of the impulsive input of the substrate at periodic time to that for the microbial growth, then the system could be controlled to be permanent, and the cultivation of the microorganism will be successful. Copyright © 2013 John Wiley & Sons, Ltd.
Accretion disk models for optical and ultraviolet microvariability in active galactic nuclei

We describe scenarios for rapid, low-amplitude UV and optical variability in AGNs through phenomenologically modeled asymmetries on accretion disks, which can represent perturbations arising from magnetic, gravitational, and other instabilities. The simulations were done for both the more familiar α-disks, where the viscous shear, t rφ , is proportional to the total pressure, as well as for the β-disk geometry, where the shear is proportional to only the gas pressure; a range of parameters for flare properties and disk structures were considered
Genetic and Floral Trait Changes in Oenothera organensis (Onagraceae) during Long-Term Ex Situ Cultivation

Premise of research. This study examines the potential effects of long-term ex situ cultivation on genetic variation and floral traits using a rare endemic species, Oenothera organensis (Onagraceae), which has been cultivated ex situ since the 1930s. Ex situ conservation in botanic gardens is an important approach to safeguard endangered plant species, especially given current threats to global biodiversity from climate change and habitat destruction. The genetic consequences of ex situ living plant cultivation include reduction in genetic diversity and inbreeding depression owing to population bottlenecks. In addition, ex situ populations might experience trait changes because of shifted or relaxed selection pressure. These changes can cause fitness declines or failure when ex situ populations are reintroduced into the wild. This study examines potential drawbacks of ex situ cultivation by focusing on neutral genetic diversity and floral traits. Methodology. To test the potential effects of ex situ cultivation on neutral genetic diversity, we used eight microsatellite markers to examine the genetic composition of multiple ex situ and wild populations of O. organensis. In addition, we applied a common-garden experiment to examine floral traits and phenology of ex situ and wild-derived populations to test whether ex situ cultivation can shift or increase the variance of floral traits. Pivotal results. The ex situ populations of O. organensis generally had reduced neutral genetic diversity and failed to capture all of the alleles observed in the wild populations. High pairwise relatedness in the ex situ population also indicated potential inbreeding. Cultivated ex situ plants exhibited higher variability in floral traits and shifted phenotypic distribution compared with wild-derived plants, which may be due to relaxed or shifted selection pressure. Conclusions. Without careful consideration and maintenance to preserve genetic variation and traits in plant populations, long-term ex situ cultivation can reduce neutral genetic diversity and change the phenotypes of conserved lineages. Most guidelines for ex situ conservation focus on increasing population sizes and pooling genetic diversity from multiple sources to maintain diversity. Our study demonstrates that relaxed or shifted selection in an ex situ setting may lead to shifted phenotypes, so management practices should also maintain ex situ plants under conditions that are as close as possible to the natural settings.
World Federation for Interventional Stroke Treatment (WIST) multispecialty training guidelines for endovascular stroke intervention

Introduction Today, endovascular treatment (EVT) is the therapy of choice for strokes due to acute large vessel occlusion, irrespective of prior thrombolysis. This necessitates fast, coordinated multi-specialty collaboration. Currently, in most countries, the number of physicians and centres with expertise in EVT is limited. Thus, only a small proportion of eligible patients receive this potentially life-saving therapy, often after significant delays. Hence, there is an unmet need to train a sufficient number of physicians and centres in acute stroke intervention in order to allow widespread and timely access to EVT. Aim To provide multi-specialty training guidelines for competency, accreditation and certification of centres and physicians in EVT for acute large vessel occlusion strokes. Material and methods The World Federation for Interventional Stroke Treatment (WIST) consists of experts in the field of endovascular stroke treatment. This interdisciplinary working group developed competency – rather than time-based – guidelines for operator training, taking into consideration trainees’ previous skillsets and experience. Existing training concepts from mostly single specialty organizations were analysed and incorporated. Results The WIST establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in EVT. WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. Conclusions WIST multispecialty guidelines outline competency and quality standards for physicians and centres to perform safe and effective EVT. The role of quality control and quality assurance is highlighted.
Gorenstein Injective and Gorenstein Flat Resolution of Modules Over Gorenstein Rings

Abstract Let R be a commutative Noetherian ring. There are several characterizations of Gorenstein rings in terms of classical homological dimensions of their modules. In this paper, we use Gorenstein dimensions (Gorenstein injective and Gorenstein flat dimension) to describe Gorenstein rings. Moreover a characterization of Gorenstein injective (resp. Gorenstein flat) modules over Gorenstein rings is given in terms of their Gorenstein flat (resp. Gorenstein injective) resolutions.
Source localization with two dimensional array subject to uncertainty in sensor location

Uncertainty in sensor locations can seriously degrade the localization capability of an array. This paper considers array calibration procedures using auxiliary sources in locations that need not be known a priori. It calculates Cramer-Rao bounds on the attainable accuracy of array geometry as well as on source bearings and ranges. It establishes conditions under which array shape can be established with arbitrary accuracy but shows that a residual error in array orientation is irremovable. This residual error translates into an irremovable error in source bearings, but not in source ranges. The bearing error can be reduced but not eliminated by proper array design. An iterative calibration procedure is proposed which appears capable of achieving errors close to the Cramer-Rao bounds for signal to noise ratios well within the practical range.
On the conjugacy and isomorphism problems for stabilizers of Lie group actions

The spaces of subgroups and Lie subalgebras with the group actions by conjugations are considered for real Lie groups. Our approach allows one to apply the properties of algebraically regular transformation groups to finding the conditions when those actions turn out to be type I. It follows, in particular, that in this case the stability groups for all the ergodic actions of such groups are conjugate (for example when the stability groups are compact). The isomorphism of the stability groups for ergodic actions is also established under some assumptions. A number of examples of non-conjugate and non-isomorphic stability groups are presented.
Enhanced star formation in the cometary globules of the Gum nebula

Evidence for an enhanced rate of star formation in the cometary globules of the Gum nebula is presented. The IRAS Point Source Catalog has been searched for sources with spectral energy distributions characteristic of young stellar or protostellar objects associated with the compact heads of the cometary globules. The surface density of such sources associated with the cometary globule heads is found to be ∼3-12 times the density in dark clouds in a neighbouring comparison area and in the northern sky. The IRAS sources associated with the cometary globule heads have luminosities in the range from ∼0.5 to ∼20 L ○ . , characteristic of low-mass young stellar or protostellar objects
Queueing Model based Dynamic Scalability for Containerized Cloud

—Cloud computing has become a growing technology and has received wide acceptance in the scientific community and large organizations like government and industry. Due to the highly complex nature of VM virtualization, lightweight containers have gained wide popularity, and techniques to provision the resources to these containers have drawn researchers towards themselves. The models or algorithms that provide dynamic scalability which meets the demand of high performance and QoS utilizing the minimum number of resources for the containerized cloud have been lacking in the literature. The dynamic scalability facilitates the cloud services in offering timely, on-demand, and computing resources having the characteristic of dynamic adjustment to the end users. The manuscript has presented a technique which has exploited the queuing model to perform the dynamic scalability and scale the virtual resources of the containers while reducing the finances and meeting up the user’s Service Level Agreement (SLA). The paper aims in improving the usage of virtual resources and satisfy the SLA requirements in terms of response time, drop rate, system throughput, and the number of containers. The work has been simulated using Cloudsim and has been compared with the existing work and the analysis has shown that the proposed work has performed better.
Evolution of the Southern Oscillation as observed by the Nimbus-7 ERB experiment

Abstract The Nimbus-7 satellite has been in a 955-km, sun-synchronous orbit since October 1978. The Earth Radiation Budget (ERB) experiment has taken approximately 8 years of high-quality data during this time, of which 7 complete years have been archived at the National Space Science Data Center. A final reprocessing of the wide- field-of-view channel dataset is underway. Error analyses indicate a long-term stability of 1% better over the length of the data record. As part of the validation of the ERB measurements, the archived 7-year Nimbus-7 ERB dataset is examined for the presence and accuracy of interannual variations including the Southern Oscillation signal. Zonal averages of broadband outgoing longwave radiation indicate a terrestrial response of more than 2 years to the oceanic and atmospheric manifestations of the 1982–83 El Nin/Southern Oscillation (ENSO) event, especially in the tropics. This signal is present in monthly and seasonal averages and is shown here to derive primarily from atmosphe.
Eigenvalues of collision operators: Properties and methods of computation

The linear Boltzmann equation for active atoms submerged in the much denser perturber gas contains a collision rate and a kernel. These two quantities are combined into a single entity\char22{}the collision operator. The collision operator possesses several interesting properties, the most important being that it is Hermitian. The eigenvalues are negative with the exception of one eigenvalue, which is zero and corresponds to the Maxwellian (steady-state) velocity distribution. A set of functions, closely related to the eigenfunctions of the quantum-mechanical harmonic oscillator, is postulated to approximate the true eigenfunctions. This assumption was a basis of the method of modeling various physical phenomena occurring in the gaseous mixtures, subjected to a radiation field. The eigenvalues of the collision operator were treated as free parameters. In this paper we establish a direct relationship between the eigenvalues and the collision integrals, or transport coefficients, known from the kinetic theory of gases. The generating function approach is employed to derive expressions yielding the eigenvalues. The obtained results form a bridge between kinetic theory, atomic physics, and quantum optics.
An Algorithm for the Traveling Salesman Problem

A “branch and bound” algorithm is presented for solving the traveling salesman problem. The set of all tours feasible solutions is broken up into increasingly small subsets by a procedure called branching. For each subset a lower bound on the length of the tours therein is calculated. Eventually, a subset is found that contains a single tour whose length is less than or equal to some lower bound for every tour. The motivation of the branching and the calculation of the lower bounds are based on ideas frequently used in solving assignment problems. Computationally, the algorithm extends the size of problem that can reasonably be solved without using methods special to the particular problem.
Tuning the surface plasmon resonance and surface-enhanced Raman scattering of pulsed laser deposited silver nanoparticle films by ambience and deposition temperature

Silver nanoparticle (AgNP) thin films were deposited by pulsed laser deposition onto glass substrates, at different fixed temperatures, under inert gas ambience and vacuum. Their morphology, surface plasmon resonance (SPR) and surface-enhanced Raman scattering (SERS) activities were investigated. AFM analysis of the films showed the formation of densely packed nanoparticles of varying size and shape by changing the ambience and deposition temperature (Ts). A SPR peak is not evidently observed in the spectrum of films deposited at room temperature, in either high vacuum or neon ambience. The SPR frequency blue shifts from 569 to 470 nm and from 581 to 574 nm with increasing Ts for the films processed in high vacuum and in neon ambience, respectively, while the absorption band becomes narrower with increasing Ts. The SERS intensity of Rhodamine B (RhB) adsorbed on a AgNP substrate grown at 600 °C in neon ambience exhibits a higher intensity compared with that of RhB adsorbed on the SERS active substrates at other values of Ts. Good correlation has been observed between the SPR and SERS activities and the morphology of the NPs.
The colour evolution of high-redshift radio galaxies

Un modele de synthese d'evolution spectrophotometrique de radiogalaxies est developpe. Les observations d'un echantillon de radiogalaxies sont comparees aux resultats numeriques pour les couleurs (R-K) et (B-R) verous le redshift. L'enveloppe rouge du diagramme R-K/Z est l'origine de la dispersion vers le bleu sont analysees
Observation of frequency band gaps in a one-dimensional nanostructured magnonic crystal

We report the experimental observation of band gaps in a synthetic nanostructured magnonic crystal composed of two different magnetic materials. The sample, in the form of a one-dimensional periodic array comprising alternating Permalloy and cobalt nanostripes, has been fabricated using advanced lithographic techniques. Dispersion relations of spin waves in the magnonic crystal have been mapped by Brillouin spectroscopy. The center frequency and width of the band gaps observed are tunable by an applied magnetic field. Dispersion relations calculated based on the finite element method accord with the measured data.