bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of image quality and standardized uptake values (SUV) of two PET/CT imaging system using F-18 and Ga-68
Authors: Alanazi S F 
Published: February 2024

Abstract
Both the Gemini TOF PET/CT and Biograph mCT flow PET/CT scanners are advanced imaging systems used in clinical settings for a range of applications, including oncology, neurology, and cardiology. Both the Gemini TOF PET/CT and Biograph mCT flow PET/CT scanners are advanced imaging systems used in clinical settings for a range of applications, including oncology, neurology, and cardiology. Both systems are capable of producing high quality images with good spatial resolution and contrast. However, there are some differences between the two systems that may impact image quality. The recovery coefficient (RC) is an important parameter that is used to evaluate the image quality and the accuracy and precision of PET/CT imaging systems. In the other hand, Standardized uptake value (SUV) is A frequently utilized quantitative measure in PET/CT imaging is the estimation of radiotracer uptake within a specified region of interest (ROI). SUV measurements are possible to be used to assess tumor metabolism and monitor treatment response. Several studies have evaluated the SUV and RC measurements using different radiotracers and scanner has been found to exhibit good accuracy and precision for both radiotracers. In this work we investigated the SUV and RC values of the Gemini TOF PET/CT and Biograph mCT flow PET/CT scanners by using F18 and Ga-68 and compared their values. Methods in this work, we analyzed images acquired using two distinct PET-CT scanners from two different manufacturers; Gemini TOF PET/CT (Philips Medical Systems) system and biograph mCT flow PET/CT system (Siemens Healthineers). we assessed the SUV values by using the PET-CT cylindrical image quality NEMA phantom that was filled with F-18 and Ga-68 while the image quality measured by employing the NEMA/International Electrotechnical Commission (IEC) Torso Phantom. Results We revealed that the RC values of F-18 using Gemini TOF PET/CT ranged from 0.02 to 0.03 for different sphere sizes, where they ranged from 0.005 to 0.015 for Ga-68 and when used Biograph mCT flow PET/CT scanner RC values of F-18 ranged from 0.025 to 0.05 and for Ga-68 ranged from 0.02 to 0.042. The first section in your paper
A fast and efficient algorithm for time synchronization in satellite quantum key distribution
Authors: Miller A V 
Published: February 2024

Abstract
Time synchronization is one of the most crucial issues that must be addressed in developing quantum key distribution (QKD) systems. It not only lets the transmitter and the receiver to assign a sequence number to each event and then do correct basis reconciliation, but also allows to increase signal-to-noise ratio. Time synchronization in satellite communications is especially complicated due to such factors as high loss, signal fading and Doppler effect. In this work, a simple, efficient and robust algorithm for time synchronization is proposed. It was tested during experiments on QKD between Micius, the world’s first quantum communications satellite, and an optical ground station located in Russia. The obtained synchronization precision lies in the range from 467 to 497 ps. The authors compare their algorithm for time synchronization with the previously used methods. The proposed approach can also be applied to terrestrial QKD systems.
Influence of the Anderson Transition on Thermoelectric Energy Conversion in Disordered Electronic Systems
Authors: Khomchenko Ilia , Ouerdane Henni , Benenti Giuliano 
Published: February 2024

Abstract
So far, the efficiency of thermoelectric energy conversion remains low compared to traditional technologies, such as coal or nuclear. This low efficiency can be explained by connecting the thermoelastic properties of the electronic working fluid to its transport properties. Such connection also shows that operating close to electronic phase transitions can be an efficient way to boost the thermoelectric energy conversion. In this paper, we analyze themoelectric efficiency close to the metal-insulator Anderson transition. Our results reveal the direct link between the thermoelectric and thermoelastic properties of Anderson-type systems. Moreover, the role of the conductivity critical exponent in the thermoelectric energy conversion is analysed. Finally, we show that relatively large values of the thermolectric figure of merit may be obtained in the vicinity of the Anderson transition.
Geant4 simulations of monochromatic Cherenkov radiation in thin quartz targets for different experimental conditions
Authors: Đurnić B , Potylitsyn A , Bogdanov A , Gogolev S 
Published: February 2024

Abstract
In light of our recent research, we discussed the possibility of observing quasimonochromatic Cherenkov Radiation (ChR) spectral lines from a dispersive medium (thin quartz radiator). Such experimental results were verified on the Mainz Microtron MAMI, Germany [1], while both the polarization currents analytical model [2] and Geant4 [3] simulations were used to analyze the results. To describe the Cherenkov radiation process, the Geant4 toolkit uses only the approximation obtainable for an infinitely thick emitter (cos θ = 1 / βn(λ), where θ is Cherenkov’s angle of emission, β is reduced velocity, and n(λ) is a refractive index as a function of emitted radiation’s wavelength λ) and doesn’t consider its actual dimensions. Tamm’s theory [4] predicts some broadening of the ChR angular distribution with a radiator thinning. Consequently, Geant4 gave inadequate results for the pencil-like electron beams compared to the polarization currents model and the experiment. However, unlike in the analytical calculations, we needed to consider more realistic Gaussian electron beams to obtain better results with Geant4. Therefore, obtained results primarily manifest beam characteristics rather than the ChR itself, i.e., its intrinsic characteristics are masked. Now, the idea is to present additional simulation results with further variations of the quartz’s thickness (in preparation for future experiments), confirming the last conclusion without any doubt.
Numerical modeling for controlled compensation grouting
Authors: Bestuzheva A S , Chubatov I V 
Published: February 2024

Abstract
This article analyzes the numerical modeling of the stress-strain state of a gravity structure sand base during grouting works using the controlled compensation grouting technique. The modeling is performed using the finite element method and physical nonlinear soil models that take into account the Coulomb-Mohr strength condition. The modeling is done in the computational software JuliS as well as the universal software complex PC ZSoil. The goal of the research is to study the impacts of compensation grouting parameters on the elevation value of base slab. A model was created for the grout body as an expanding spheroid whose volume changes as cement grout is fed in the soil. The authors developed a grouting sequence for grouting solutions based on the location of grout body in the grouting pillar. It is more efficient to feed the grout starting from the lower grout body. The grouting solution feed mode is selected depending on the soil strength condition and accounting for the prevention of hydraulic fracture. As a result of the research, the initial subsidence of the soil on the daytime surface above the injection zone was obtained, which requires experimental confirmation and is a matter for discussion.
Gaussian Process-based Bayesian Optimization and Shape Transformation of Benchmark Functions
Authors: Omae Yuto 
Published: February 2024

Abstract
Gaussian process-based Bayesian optimization (GPBO) finds application in various fields for approximate optimization of parameters. Because the search performance depends on the shape of the black-box function, users of GPBO should know these details. Therefore, we provide some experiment results of the relationship between GPBO search performance and the shape of the black-box function. We adopted “Easom,” “Ackley,” “Bukin N.6,” “Beale,” “Rosenbrock,” and “Goldstein–Price,” which are benchmark functions for optimization problems. Moreover, we adopted logarithmic and range-transformed functions to provide deeper insight.
Simulation model parameter optimization method for multidimensional signals
Authors: Rozanov Ivan , Sotnikov Alexey , Kim Tamara 
Published: February 2024

Abstract
The paper describes an approach to minimize the number of simulation experiments of multidimensional signals by means of a regression neural network. Multivariate signal simulation systems are in demand for testing real-time computing systems, but they mostly have a wide vector of model parameters. The formation of parameter vector for the simulation model of multidimensional signals, which ensures an adequate solution to the problem of signal processing obtained as a result of the model operation, is an urgent task. The authors propose a method of heuristic optimization of input parameters, implemented by means of machine learning, which reduces the searching of values for the given optimization function. In this study the ability to perform real-time signal simulations is the optimization feature. The research outcomes are the description of the neural network, the rationale for its configuration, and the training and validation results.
3D scanning in Cultural Heritage: model creation and digital restoration of the tombstone of the bishop Vasilije Petrović (Negosh) in Saint Petersburg
Authors: Badillo P. D. , Parfenov V. A. , Raspopović R. , Tishkin V. O. 
Published: February 2024

Abstract
3D laser and optical scanning techniques are widely employed in Cultural Heritage preservation for documenting pieces of different sizes and shapes. However, due to limitations of the methods available today, the results obtained vary according to different characteristics of the object under study. External surfaces showing very smooth features make the capturing process and the posterior processing a more elaborate task, requiring special attention and additional retouching to improve the final 3D model. Tombstones are a typical example of this type of objects, combining both flat external contours and refined outlines. In this work the procedure of creation of the digital model of the tombstone of the bishop Vasilije Petrović (Negosh) is described, a piece of art which combines both technical and historical importance. Post-processing steps required involved different software (Geomagic Design X, ZBrush, Adobe Photoshop) for surface correction and cleaning, details and photorealistic texture improvements and lost material restoration.
Semi-empirical method for evaluating the robustness of QRWS algorithm for different coin sizes and functional dependence between coin phases
Authors: Tonchev H , Danev P 
Published: February 2024

Abstract
In this work we study the quantum random walk search algorithm when the walk coin is constructed by generalized Householder reflection and a phase multiplier. We focus on the algorithm’s robustness against errors in the phases – how the probability to find solution decreases with increasing the errors in those phases. The robustness depends on the functional dependence between the reflection phase φ and the phase multiplier ζ. Here we use interpolations by non-linear logistic regression functions to study a particular functional dependence between angles ζ = -2φ + 3π + α sin(2φ) for different coin sizes and parameters alpha. The obtained results in this work are discussed, together with their limitations.
The multifractality of the internal geomagnetic field
Authors: Peqini Klaudio 
Published: February 2024

Abstract
It is well established that the external geomagnetic field exhibits distinct multifractal behaviour with multiple characteristic timescales that are a manifest of the complex solar-driven dynamics of the magnetosphere or ionosphere. The internal magnetic field on the other hand is characterized by much longer timescales. Consequently, in order to observe any multifractal behaviour, there is needed a time series of magnetic dipolar moment spanning thousands or even millions of years of the past geomagnetic field of the core. Here, we analyse two series that describe the dipolar ingredient of the geomagnetic field for the last 4 and 2 million years, respectively. The first series is constructed from a continuous streak of sedimentary samples while the other series is a composite of a myriad of shorter time series contained within the 2 million years frame. We analysed the Generalized Hurst Exponent through the Multi Fractal-Detrended Fluctuation Analysis method and in each case, we observed typical multifractal structures. These results may be the manifestation of different phenomena evolving in the liquid outer core, possibly providing hints and insights into the details of the corresponding mechanisms. Analysis of the time evolution of the Generalized Hurst Exponent for each series displays a complicated behaviour. Typically the anti-persistent character of the series becomes more evident when close to e dipole reversal. Special efforts need to be dedicated in identifying connections between geomagnetic reversals and time dependence of the Generalized Hurst Exponent.
Numerical simulation of image formation in an optical device in the problem of space monitoring
Authors: Vafin K M , Kuznetsov A A , Zavialova N A , Negodiaev S S 
Published: February 2024

Abstract
Space monitoring systems are being developed for space object and debris observation. There are the following problems in this area: optimizing the operation of existing optoelectronic devices, locating new devices, analyzing the monitoring results of outer space. It is necessary to use modeling in order to solve these problems. In this regard, the authors aimed to investigate the process of image formation on a photodetector under specified observation conditions. A mathematical model of image formation was constructed and a software implementation of this model was developed. Synthetic images of the night sky and images of the trajectories of space objects under given conditions were formed. The obtained results were compared with real images from telescopes.
Discrepancies between reported knuckleball spin rates and dynamics
Authors: Hoskins Aaron B 
Published: February 2024

Abstract
Major League Baseball tracks every pitch of every game and provides the public with access to a significant amount of data for each pitch. This level of data availability is not seen in many other sports and offers substantial opportunities to provide analysis on the sport. Major League Baseball does not provide the raw data but provides refined data. While the algorithms for transforming the raw data are robust, the algorithms are not perfect. This study investigates the specific case of knuckleball pitches and shows that the equations of motion and reported spin rates do not align. This study uses the modified shooting method combined with the Levenberg–Marquardt algorithm to determine the trajectories of the pitches based on the provided data and known equations of motion. This study investigates three scenarios: 1) the reported data are correct; 2) the pitches are correctly identified, but the spin rates are incorrect; and 3) the spin rates are correct, but the pitches are incorrectly identified as knuckleballs. We show that the reported data are inconsistent with the equations of motion and that, based on statistical analysis, the pitch identification is likely incorrect.
Building Empathy in Students by Developing Cyber-Physical Projects Through Design Thinking
Authors: Stoev Petko , Stoeva Maya 
Published: February 2024

Abstract
Empathy is a fundamental aspect of human behavior through which people build civilized social and interpersonal relationships. It is related to showing empathy, understanding and support, forming effective communication, dealing with conflict and is part of those factors that contribute to building a more compassionate and humane society. Despite its innate predisposition, the development of empathy is influenced by a number of factors, including learning. Developing projects through design thinking can be an effective way to foster and cultivate it in students. Applying a human-centered method such as design thinking to the process of project work enables them to develop a deeper understanding of others, build empathy, and generate solutions that respond to real-world problems. This paper explores the possibilities for achieving this goal and presents the results of a project-based learning experience integrating design thinking
Inverse Problem of Parameter Identification for Extended Compositional Gradient Model
Authors: Kusochkova E V , Indrupskiy I M 
Published: February 2024

Abstract
In this study we address simulation of initial distribution of fluid composition in hydrocarbon reservoirs, particularly in scenarios where slow vertical segregation in a low-permeability near-critical reservoir results in an incomplete relaxation to the quasi-equilibrium state. To effectively analyze these complex scenarios, we propose an extended compositional gradient model that takes into account incomplete system relaxation. Practical application of the method involves solution of the forward problem of compositional profiling, with the model parameters adjusted according to real fluid samples. We formulate the inverse problem of parameter identification for the extended compositional gradient model and solve it using gradient-free optimization methods. The adjusted parameters are specific enthalpies of fluid components and the relaxation parameter. The overarching goal of parameter identification is to closely match the predictions of the model with real data, thereby enhancing the reliability of forecasts regarding distribution of fluid composition. We believe that the results of this study will significantly influence both understanding and simulation techniques for distribution of hydrocarbon components in natural reservoirs, particularly in situations characterized by incomplete system relaxation.
Updated BBN constraints on non-equilibrium active-sterile neutrino oscillations
Authors: Panayotova Mariana , Kirilova Daniela 
Published: February 2024

Abstract
Big Bang Nucleosynthesis (BBN) offers impressive agreement between the predicted by theory and the observationally obtained abundances of primordially produced light elements and therefore it is used as one of the most reliable probes of the physics beyond Standard Model. The highly accurate recent determination of the primordial Deuterium and Helium-4 allows to provide updated and strengthened BBN constraints on beyond Standard Model Physics. We have provided numerical analysis of more than hundred BBN models with nonequilibrium electron-sterile neutrino oscillations with different oscillation parameters and we have constructed isohelium contours based on 1% and 3% Helium-4 uncertainty and different initial population of the sterile neutrino state. We present here updated and more strict BBN constraints on the parameters of non-equilibrium active-sterile neutrino oscillations considering several models of beyond Standard Model Physics.
Diamagnetic corrections to low-excited electronic states of light molecular systems
Authors: Danev P , Tonchev H , Stoyanov Zh , Mutafchieva Y 
Published: February 2024

Abstract
Compact astrophysical objects like white dwarfs and neutron stars generate very strong magnetic fields. In their atmosphere, accretion disks, and the interstellar medium surrounding them, the predominant matter consists of hydrogen, helium and few-particle atoms and molecules. In this work, we have studied the effects of strong magnetic fields on light atomic and molecular systems like hydrogen molecular ions and antiprotonic helium. The full energy of the investigated systems is calculated in the Born-Oppenheimer approximation for a few low-lying electronic states. We investigate the case where the leading effect comes from the quadratic magnetic field term in the interaction Hamiltonian. The electronic energies and wavefunctions are computed in spheroidal coordinates by a finite difference method on a nonequidistant grid. The diamagnetic contributions to the total energy for an arbitrary value of the magnetic field strength are also calculated in perturbation theory. Then they are compared with the exact results, and where possible - with previous calculations. The electronic energy terms could be used for precise computations of the spectral lines of the hydrogen molecular ion and antiprotonic helium. This will allow searching for objects, like neutron stars and white dwarfs with strong magnetic fields, containing such molecular systems in their atmospheres or accretion discs. When the effects from the approximations are taken into account, the tabulated results presented in this work could also find an application in studies for much weaker magnetic field strengths existing in laboratory environments.
Increasing of Compression Efficiency for Genomic Data by Manipulating Empirical Entropy
Authors: Aldemir Erdoğan , Oğraş Hidayet 
Published: February 2024

Abstract
Sharing bio-informatics data is the key point to constructing a mobile and effective telemedicine network that brings with it various difficulties. A crucial challenge with this tremendous amount of information is storing it reversibly and analysing terabytes of data. Robust compression algorithms come up with a high rate of text and image compression ratios. However, the achievement of these advanced techniques has remained in a limited range since, intrinsically, the entropy contained by the raw data primarily determines the efficiency of compression. To enhance the performance of a compression algorithm, entropy of raw data needs to be reduced before any basic compression which reveals more effective redundancy. In this study, we use reversible sorting techniques to reduce the entropy thus providing higher efficiency in the case of integrating into compression technique for raw genomic data. To that end, permutation-based reversible sorting algorithms, such as Burrow-wheeler, are designed as a transform for entropy reduction. The algorithm achieves a low-entropy sequence by reordering raw data reversibly with low complexity and a fast approach. The empirical entropy, a quantitative analysis, shows a significant reduction of uncertainty has been achieved.
Mathematical Modeling of Consciousness for Unifying Causation, Relativity and Quantum Mechanics
Authors: Samarawickrama Mahendra 
Published: February 2024

Abstract
Quantum physics and gravity are two different concepts which need to be unified in a widely acceptable way. While electromagnetism, weak nuclear force, and strong nuclear force were accurately unified under the framework of quantum field theory, gravity remains elusive and couldn’t be unified with quantum mechanics. However, gravity is accurately understood by the theory of relativity, which is not complementing quantum physics. This elusiveness is due to the missing consciousness dimension in the mathematical frameworks of fundamental physics, which can explain the causation of gravity, quantum mechanics, and reality. Intricately interweaving the dimension of consciousness with the mathematical frameworks of fundamental physics can make our understanding of reality complete.