Coefficient Ratio Research Articles

Altitude-dependent variations in some morphological and anatomical features of Anatolian chestnut

Morphological measurements of Anatolian chestnut (Castanea sativa Mill.) leaves were done within the borders of Abana district of Kastamonu province. The study was conducted using mixed (oak, beech, hornbeam, black pine, and yellow pine) medium (41% to 70%) and fully closed (71% to 100%) stands. Some leaf parameters, such as leaf blade width, petiole length, leaf blade length, leaf length, distance between lateral veins, teeth width, teeth length, the angle between the leaf base and the petiole, and the angle between the midrib and lateral veins, were measured. Moreover, stomata of the leaves picked up from precise altitudes were observed under a scanning electron microscope. The differences between fibre elevation, fibre wall thickness, elasticity coefficient, rigidity coefficient, Muhlstep rate, and Runkel ratio were found in the wood samples taken from different altitude zones. It was found that altitude did not affect leaf blade width, fibre length, fibre width, felting ratio, and lumen width. However, it was determined that altitude affected other studied characteristics.

Application of design of experiments for single-attribute optimization using response surface methodology for flow over non-linear curved stretching sheet

Optimizing the heat transmission rate of the flow through the statistically designed chain of experiments has major applications in product designing and improvising. Here, statistic design is framed by implementing response surface optimization methodology to contemplate the flow of dual non-Newtonian fluids allowed to flow over non-linear stretched geometry. The fluid flow model is designed under Cattaneo-Christov diffusion theory over a magnetized-radiative surface. The boundary condition is enriched with the slip regime and Newtonian heating. Numerical computations are acquired by employing the shooting technique approach in association with Runge-Kutta Fehlberg numerical scheme. Statistical and numerical consequences disclose that non-linear stretching index causes a depletion in velocity and temperature. When the Eckert number and the heat generating parameter are both large, the heat transfer rate is also large. Mass transport rate is lowest for higher ratios of diffusion coefficients. The 0.265365 is the maximum possible heat transport rate attained for the 8th experimental run with the key elements: Eckert number, heat source and radiation parameter. The critical point claimed by the Pareto chart shows that the slightest manipulation of the radiation parameter is critical for the heat transport rate, whereas the heat source parameter and Eckert number have almost similar influences on the response.

Bearing Behavior of Engineered Cementitious Composite and Ultra-High-Performance Concrete Filled-In Double Steel Tubular Composite Columns Subjected to Eccentrical Load

To study the eccentric compression mechanical properties of ECC and UHPC filled-in double steel tubular (EUFDST) composite columns, 35 full-scale EUCFDST composite column specimens were designed by ABAQUS software with the slenderness ratio (λ), UHPC cylinder compressive strength (fcu), inner and outer steel tubular strength (fy1, fy2), inner and outer steel tubular thickness (t1, t2), inner and outer steel tubular diameter ratio (Ω), eccentricity (e), and fiber content (γ) as the main parameters. By comparison with the simulation of the existing test, the correctness of the finite element modeling is verified. The parameter analysis of 35 full-scale EUFDST composite columns was carried out to obtain the eccentric load-mid-span deflection curve of the specimens. The failure mechanism, ductility coefficient, and stiffness degradation of the composite columns under different parameters were analyzed, and the section of the composite column was verified to satisfy the plane section assumption. The variation trend of maximum load-bearing capacity and the ductility of composite columns under different parameter conditions was obtained. By introducing the eccentricity correction coefficient and slenderness ratio correction coefficient, the calculation equation of the eccentric maximum load-bearing capacity of EUCFDST composite columns is statistically regressed, which provides a basis for the practical use of these columns.

Material Classification Map Using Dual-Energy Method at Low-Energy X-Ray Spectrum: An Experimental and Monte Carlo Simulation Study

Abstract The objective of this article is to develop an effective method for material discrimination, distinguishing specifically between light metallic materials and heavy ones at low X-ray energies. In this research, Monte Carlo simulations are employed to investigate the influential factors affecting material discrimination. Initially, for result validation, the experimental setup is fully simulated based on the Monte Carlo method. The X-ray spectrum of 160 keV is simulated, and then it is registered after interacting with step wedges made of iron, aluminum, graphite, and ABS at specific thicknesses, capturing the radiation flux at each step. The results are compared with the experimental findings obtained from a dual-layer detector, demonstrating excellent agreement. In practice, the dual-layer detector comprises a low-energy GOS detector, a copper filter, and a high-energy CsI(Tl) detector. The energy spectra of the registered X-rays on each layer of detectors are obtained using the Monte Carlo method. Materials with low, medium, and high atomic numbers are chosen for analysis. These materials are categorized into three groups: organic materials (comprising both light and heavy organic and biological substances), light metals, and heavy metals. Discrimination between materials is achieved independently of their thickness by utilizing a material classification map (MCM) derived from a graph depicting the transmission ratio of low-energy X-ray photons versus the linear attenuation coefficient ratio for various materials with different atomic numbers. The results have been successfully validated through testing with various materials and thicknesses using both the experimental setup and Monte Carlo simulations.

Effects of granite stratum with different weathering levels on water discharge in metro tunnels

This paper proposes a method for calculating the water discharge in metro tunnels considering limited drainage. With this method, groundwater resources and vegetation can be protected on the premise of ensuring the structural safety of tunnel linings. The water discharge in drainage-limited tunnels constructed through weathered granite was investigated. The water discharge characteristics were explored under different parameters of the shotcrete layer and grouting ring. The effects of the thickness and permeability coefficient of the weathered granite strata on the water discharge in the tunnel were discussed and the results were validated by in-situ monitoring of the water discharge. The results showed that the water discharge decreases with the increase in the thickness ratio of the grouting ring and shotcrete layer and with the decrease in the permeability coefficient ratio of the shotcrete layer and grouting ring. The water discharge can be effectively reduced by increasing the thickness or decreasing the permeability coefficient of the grouting ring. Once the ratio of the grouting ring to the thickness of the shotcrete layer exceeds 20, the water discharge no longer decreases significantly, and by tuning the parameters of the grouting ring, tunnel construction costs can be reduced without affecting the groundwater resource or vegetation around the tunnel. The proposed method can serve as a basis for regulating the water discharge in tunnels located in ecologically fragile regions.

OPTIMIZATION OF GEOMETRY OF PIEZORESISTIVE EFFECT ON THE EXAMPLE OF CUBIC CRYSTALS

On the example of semiconductor crystals Ge, Si, PbTe, PbS, InSb with different levels of doping and different types of conductivity, the geometry of the piezoresistive effect was optimized, namely, such directions of voltage measuring and uniaxial pressure applying were determined, which ensure the maximum achievable value of the effect. The optimization is based on an approach using the construction and analysis of extreme surfaces that represent all possible maxima of the objective function (the magnitude of the effect) under different spatial orientations of interacting factors. The optimization parameters were the angles that determine the directions of the unit vectors of the directions of current and uniaxial pressure applying. The directions of the radius vectors of the points on the extreme surface coincide with the ones in which the electric voltage is measured, and the length of this radius vector for each point was determined by setting such optimization parameters for which the magnitude of the effect for a given direction of voltage measuring would be maximal. It is shown that the optimal interaction geometry in most of the studied cases is longitudinal, and only for n-PbTe, p-InSb crystals it is transverse (although not identical), and the optimal directions for the studied crystals are <100>, <110> or <111> depending on the composition of the crystal and the type of doping. Despite the fact that all investigated crystals belong to the same point symmetry group (m3m), the shapes of the extreme surfaces for them are significantly different, which is caused by different ratios between the piezoresistive coefficients. Typical forms of extreme surfaces have been identified, and in order to explain the obtained results, an analysis of limiting cases that differ in the ratio of piezoresistive coefficients has been carried out. Based on this analysis, four main types of extreme surfaces were established. A scheme has been built that allows, in the case of cubic crystals, to estimate the type of extreme surface and the corresponding optimal directions of voltage measuring, current density (for cubic crystals, these directions coincide) and uniaxial pressure applying. On the basis of this scheme, the forms of extreme surfaces obtained for the investigated crystals are explained.

Beam quality conversion factor of BeO-OSLD for high-energy photon beams

Optically stimulated luminescence (OSL) dosimeters are used in radiotherapy. The beam quality conversion factor (kQ) of dosimeters is essential for correcting energy dependence. However, the kQ of an OSL dosimeter using BeO (BeO-OSLD) has not yet been reported for high-energy photon beams. In this study, the kQ of BeO-OSLD was investigated for high-energy photon beams using experiments and Monte Carlo calculations. In the experiments, kQ was evaluated as the ratio of calibration coefficients determined using high-energy photon beams and 60Co γ-rays. Ten OSL dosimeters were used to reduce the statistical uncertainty of the determined kQ values, and the same dosimeters were repeatedly used to obtain the data set of high-energy photon beams and 60Co γ-rays. Pre-irradiation with 10 Gy and bleaching were performed on fresh dosimeters before dosimetry to reduce the dependence of the detector response on the accumulated dose. In Monte Carlo calculations, both the absorbed dose to water and that of the BeO dosimeter for high-energy photon beams and 60Co γ-rays were calculated, and then kQ was determined using the ratio of these values. The determined kQ values in high-energy photon beam were 0.998 ± 0.011 and 1.021 ± 0.005 for the experiment and the calculation, respectively. These results showed that the variation in kQ for 6–25 MV was negligible in practical dosimetry. This result indicates that BeO can be used to evaluate doses for different beam qualities without correcting for energy dependence.

Japanese value set for the EORTC QLU-C10D: A multi-attribute utility instrument based on the EORTC QLQ-C30 cancer-specific quality-of-life questionnaire

PurposeThis study aimed to develop a Japanese value set for the EORTC QLU-C10D, a multi-attribute utility measure derived from the cancer-specific health-related quality-of-life (HRQL) questionnaire, the EORTC QLQ-C30. The QLU-C10D contains ten HRQL dimensions: physical, role, social and emotional functioning, pain, fatigue, sleep, appetite, nausea, and bowel problems.MethodsQuota sampling of a Japanese online panel was used to achieve representativeness of the Japanese general population by sex and age (≥ 18 years). The valuation method was an online discrete choice experiment. Each participant considered 16 choice pairs, randomly assigned from 960 choice pairs. Each pair included two QLU-C10D health states and life expectancy. Data were analyzed using conditional logistic regression, parameterized to fit the quality-adjusted life-year framework. Preference weights were calculated as the ratio of each dimension-level coefficient to the coefficient for life expectancy.ResultsA total of 2809 eligible panel members consented, 2662/2809 (95%) completed at least one choice pair, and 2435/2662 (91%) completed all choice pairs. Within dimensions, preference weights were generally monotonic. Physical functioning, role functioning, and pain were associated with the largest utility weights. Intermediate utility weights were associated with social functioning and nausea; the remaining symptoms and emotional functioning were associated with smaller utility decrements. The value of the worst health state was − 0.221, lower than that seen in most other existing QLU-C10D country-specific value sets.ConclusionsThe Japan-specific QLU-C10D value set is suitable for evaluating the cost and utility of oncology treatments for Japanese health technology assessment and decision-making.

Extrapolating time development curves of clear-water scour around piles: From empirical fitting to physics-based approach

The currently available prediction formulas for the scour development around a pile predominantly rely on empirical fittings, lacking clear physical mechanisms. This study integrates the principle of sediment mass conservation, the flat-bed sediment transport model, and the phenomenological theory of turbulence to propose a semi-analytical model for predicting clear-water scour development around circular piles. This model overcomes scale-related issues and is governed by three fundamental parameters: the equilibrium scour depth, the characteristic time, and the ratio of the scour depth coefficient to the primary horseshoe vortex coefficient. The results demonstrate that the proposed model is consistent with experimental data. The proposed model offers significant improvements by addressing two critical issues observed in existing models: (i) empirical formulas expressed purely in mathematical terms exhibit low prediction accuracy for long-term scour, resulting in underestimation of the extrapolated equilibrium scour depth and premature attainment of equilibrium conditions; (ii) other models exhibit a divergence phenomenon, where the extrapolated equilibrium scour depth greatly exceeds the pile diameter, contradicting prevailing understanding. Applying the proposed model allows for a substantial reduction in test duration while accurately capturing the subsequent scour development process.

Animal PET scanner with a large field of view is suitable for high-throughput scanning of rodents.

In preclinical studies, high-throughput positron emission tomography (PET) imaging, known as simultaneous multiple animal scanning, can reduce the time spent on animal experiments, the cost of PET tracers, and the risk of synthesis of PET tracers. It is well known that the image quality acquired by high-throughput imaging depends on the PET system. Herein, we investigated the influence of large field of view (FOV) PET scanner on high-throughput imaging. We investigated the influence of scanning four objects using a small animal PET scanner with a large FOV. We compared the image quality acquired by four objects scanned with the one acquired by one object scanned using phantoms and animals. We assessed the image quality with uniformity, recovery coefficient (RC), and spillover ratio (SOR), which are indicators of image noise, spatial resolution, and quantitative precision, respectively. For the phantom study, we used the NEMA NU 4-2008 image quality phantom and evaluated uniformity, RC, and SOR, and for the animal study, we used Wistar rats and evaluated the spillover in the heart and kidney. In the phantom study, four phantoms had little effect on imaging quality, especially SOR compared with that for one phantom. In the animal study as well, four rats had little effect on spillover from the heart muscle and kidney cortex compared with that for one rat. This study demonstrated that an animal PET scanner with a large FOV was suitable for high-throughput imaging. Thus, the large FOV PET scanner can support drug discovery and bridging research through rapid pharmacological and pathological evaluation.

Static characteristics of a biomimetic robot module driven by water hydraulic artificial muscles resisted with helical spring

Soft modular biomimetic robots, driven by flexible actuators, are extensively used in various fields due to their excellent flexibility, environmental adaptability, and isomorphism. However, existing flexible modules typically possess no more than two degrees of freedom for structural limitations. This paper proposes a biomimetic robot module supported by a spring and actuated by water hydraulic artificial muscles (WHAMs). Combining the mechanical properties of WHAMs and spring, the static model of the soft module was established by force balance method. Moreover, the contraction force coefficient and contraction ratio coefficient of WHAMs were identified through the static characteristics test. The rod length coefficient and stress coefficient of the spring were also identified through the spring bending test. The errors between the experimental results and the model are analyzed and discussed, uncovering the main reasons. The influence of spring pre-compression, spring elasticity coefficient, initial working pressure of WHAM, and the installation distance of WHAM on the motion space of module were analyzed and discussed. This work serves as a guide for the structural design of flexible modules to meet specific requirements and lays the foundation for future research on integrated flexible biomimetic robots driven by WHAMs.

Thermal expansion, lattice vibration, and isotope effect on hydrogen diffusion in BCC Fe, Cr, and W from first-principles calculations.

Fe, Cr, and W are important elements in the alloys of in-reactor materials and operate in high-temperature environments with thermal expansion. Their tritium-impeding abilities are crucial to the radiation safety of various nuclear reactors. In this study, first-principles density functional theory is combined with quasi-harmonic approximation to evaluate factors that can affect the interstitial formation energy and diffusion coefficient of hydrogen isotopes in body-centered cubic (BCC) Fe, Cr, and W, including thermal expansion, metal host lattice vibrations, phonon density-of-states (pDOS) coupling diffusing atoms, and isotope effects. Calculation results indicate that the interstitial formation energy decreases as lattice expansion increases, whereas the jump barriers remain almost constant. Thermal expansion, host lattice vibration, and pDOS coupling minimally affect the diffusion coefficients of hydrogen isotopes in Fe, Cr, and W. The diffusion coefficient ratios between hydrogen isotopes are higher than the inverse ratio of the square root of the isotope mass at low temperatures. However, they decrease to the inverse ratio of the square root of the isotope mass at temperatures exceeding 800K. This study comprehensively investigates factors that affect the diffusion coefficients of hydrogen isotopes in BCC Fe, Cr, and W, thus providing a firm theoretical foundation for predicting the diffusion coefficients of tritium at different temperatures using protium/deuterium diffusion coefficients.

Whole-genome resequencing revealed the population structure and selection signal of 4 indigenous Chinese laying ducks

The assessment of animal genetic structure had significant importance for the preservation and breeding of animal germplasm resources. Selection signals are genotype markers generated during the process of biological evolution, and the detection of selection signals could reveal the direction of species evolution. The aim of this study was to generate a whole-genome resequencing data from Jinding duck, Shanma duck, Youxian Partridge duck, and Taiwan Brown tsaiya duck to reveal their population structure and selection signals. The population structure analysis revealed significant genetic differences among the 4 indigenous laying ducks, indicating their independent lineage. Specifically, Shanma duck and Youxian partridge duck were closely and likely originated from a common ancestor. In addition, selection sweep analysis was performed using the population genetic differentiation coefficient (Fst) and nucleotide diversity ratio (π ratio). The top 5% was used as the threshold for the Fst and π ratio, and the 2 thresholds were combined to identify selected genomic regions. In the selected regions of the 3 comparison groups, 136, 143, and 268 candidate genes were detected. Further screening of all candidate genes revealed that 35 candidate genes appeared simultaneously in 3 comparative groups, with 16 genes annotated. The 16 genes were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The results revealed 5 functional genes (AQP3, PIK3C3, NOL6, RPP25, and DCTN3) that may be related to important economic traits in laying ducks and involved mainly invasopressin-regulated water reabsorption, ribosome biogenesis, and the PI3K signaling pathway. The results provide insights into the protection and exploitation of genetic resources of Chinese indigenous laying ducks.

Reflection of Waves in a Two-Temperature Magneto-fiber-Reinforced Solid with Memory-Dependent Derivative Using Different Theories

Abstract Purpose The problem is concerned with the analysis of the reflection of the waves through a fiber-reinforced thermoelastic medium under the effect of the magnetic field, gravity, and the initial stress. The problem is discussed in the context of the three-phase-lag model and Green-Naghdi theory of type II and III with the memory-dependent derivative and variable thermal conductivity. Methods The harmonic representation of waves is used to find the solution to the problem. Based on the solution, it is concluded that after reflection three quasi-waves propagate through the medium. Results Numerical computations were performed using MATLAB software. The reflection coefficient ratio variations with the angle of the incident are shown graphically. Conclusion Comparisons are made with the results predicted for different values of the thermal conductivity parameter, two-temperature parameter, initial stress, gravity field, and different values of the magnetic field.

Physical, rheological and micro characteristics of ARA/Nano-TiO2 composite modified asphalt before and after short-term aging

This paper aims to investigate the composite application of nanomaterials and natural asphalt in order to enhance the road performance of asphalt pavement. The objective is to develop high-performance modified asphalt that improves the durability, reliability, and load resistance of asphalt roads while reducing resource waste and environmental pollution. The composite modified asphalt was prepared by adding different blends of Albanian natural rock asphalt (ARA) and 1% of nano titanium dioxide (Nano-TiO2), and the basic properties and rheological properties of the asphalt before and after aging were tested by using basic performance tests and temperature scanning tests. Subsequently, the microscopic morphological characteristics of the asphalt were observed by scanning electron microscope and atomic force microscope, and the number of bee structures, the area share of bee structures, root mean square roughness Rq, and arithmetic mean roughness Ra were used as microscopic quantitative indexes. The results indicate that the complex modulus and rutting coefficient of ARA/Nano-TiO2 composite-modified asphalt increase with an increase in ARA dosage when the dosage of Nano-TiO2 is 1%. The asphalt modified with Nano-TiO2 composite blended with 15% ARA exhibits higher residual needle penetration, composite modulus ratio, rutting coefficient ratio and lower softening point increment compared to 70# asphalt. The bitumen modified with titanium dioxide nanocomposite blended with 15% ARA exhibits higher Rq and Ra and a more stable phase structure before and after aging. 15% of ARA/Nano-TiO2 composite-modified asphalt has higher Rq and Ra before and after aging, and its phase structure is more stable. The results show that ARA/Nano-TiO2 composite-modified asphalt has better high-temperature deformation resistance and aging resistance than 70# and that 15% ARA is recommended as the optimum amount of composite-modified asphalt.

Feasibility of compacted attapulgite/diatomite amended clayey soils as gas barrier materials

Compacted clay liners are extensively used as barriers to control the upward diffusion of vapors of volatile or semi-volatile organic contaminants released from unsaturated contaminated soils at industry-contaminated sites. This study aimed to investigate the gas diffusion barrier performance of compacted clayey soils amended with three agents including attapulgite and diatomite individually, and attapulgite/diatomite mixture. The properties including water retention, volumetric shrinkage, gas diffusion, and unconfined compressive strength were evaluated through a series of laboratory tests of amended compacted clayey soils. The results demonstrate that the decrease in volume proportions of inter-aggregate pores leads to an increase in unconfined compressive strength (qu). Both hydrophilic groups and microstructures of attapulgite and diatomite result in an increase in water retention percent (Wt) of compacted clayey soil specimens after amendment regardless of the type of agent or initial water content (w0). Furthermore, the ratio of the gas diffusion coefficient (De) to the gas diffusion coefficient in the air (Da) was significantly reduced owing to a decrease in volume proportions of inter-aggregate pores, hydrophilic group, and microstructures of attapulgite and diatomite. Scanning electron microscope analyses revealed that rod-shaped attapulgite filled the inter-aggregate pores formed by clay particles, whereas the disc-shaped diatomite particles, characterized by micropores, failed to obstruct the inter-aggregate pores due to their larger particle size. Mercury intrusion porosimetry (MIP) analyses showed a reduction in pore volume in the inter-aggregate pores, leading to a reduction in the total pore volume for both the attapulgite and attapulgite/diatomite mixture amended clays, which is in accordance with the scanning electron microscope (SEM) results. The findings are pertinent to the practical application of compacted clay liners as gas barriers against the upward migration of volatile or semi-volatile organic contaminants at contaminated sites.

In situ electric-field control of ferromagnetic resonance in the low-loss organic-based ferrimagnet V[TCNE]x∼2

We demonstrate indirect electric-field control of ferromagnetic resonance (FMR) in devices that integrate the low-loss, molecule-based, room-temperature ferrimagnet vanadium tetracyanoethylene (V[TCNE]x∼2) mechanically coupled to PMN-PT piezoelectric transducers. Upon straining the V[TCNE]x films, the FMR frequency is tuned by more than 6 times the resonant linewidth with no change in Gilbert damping for samples with α = 6.5 × 10−5. We show this tuning effect is due to a strain-dependent magnetic anisotropy in the films and find the magnetoelastic coefficient |λs| ∼ (1–4.4) ppm, backed by theoretical predictions from density-functional theory calculations and magnetoelastic theory. Noting the rapidly expanding application space for strain-tuned FMR, we define a new metric for magnetostrictive materials, magnetostrictive agility, given by the ratio of the magnetoelastic coefficient to the FMR linewidth. This agility allows for a direct comparison between magnetostrictive materials in terms of their comparative efficacy for magnetoelectric applications requiring ultra-low loss magnetic resonance modulated by strain. With this metric, we show V[TCNE]x is competitive with other magnetostrictive materials, including YIG and Terfenol-D. This combination of ultra-narrow linewidth and magnetostriction, in a system that can be directly integrated into functional devices without requiring heterogeneous integration in a thin film geometry, promises unprecedented functionality for electric-field tuned microwave devices ranging from low-power, compact filters and circulators to emerging applications in quantum information science and technology.

MRI Scoring Systems for Predicting Isocitrate Dehydrogenase Mutation and Chromosome 1p/19q Codeletion in Adult-type Diffuse Glioma Lacking Contrast Enhancement.

Background According to 2021 World Health Organization criteria, adult-type diffuse gliomas include glioblastoma, isocitrate dehydrogenase (IDH)-wildtype; oligodendroglioma, IDH-mutant and 1p/19q-codeleted; and astrocytoma, IDH-mutant, even when contrast enhancement is lacking. Purpose To develop and validate simple scoring systems for predicting IDH and subsequent 1p/19q codeletion status in gliomas without contrast enhancement using standard clinical MRI sequences. Materials and Methods This retrospective study included adult-type diffuse gliomas lacking contrast at contrast-enhanced MRI from two tertiary referral hospitals between January 2012 and April 2022 with diagnoses confirmed at pathology. IDH status was predicted primarily by using T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign, followed by 1p/19q codeletion prediction. A visual rating of MRI features, apparent diffusion coefficient (ADC) ratio, and relative cerebral blood volume was measured. Scoring systems were developed through univariable and multivariable logistic regressions and underwent calibration and discrimination, including internal and external validation. Results For the internal validation cohort, 237 patients were included (mean age, 44.4 years ± 14.4 [SD]; 136 male patients; 193 patients in IDH prediction and 163 patients in 1p/19q prediction). For the external validation cohort, 35 patients were included (46.1 years ± 15.3; 20 male patients; 28 patients in IDH prediction and 24 patients in 1p/19q prediction). The T2-FLAIR mismatch sign demonstrated 100% specificity and 100% positive predictive value for IDH mutation. IDH status prediction scoring system for tumors without mismatch sign included age, ADC ratio, and morphologic characteristics, whereas 1p/19q codeletion prediction for IDH-mutant gliomas included ADC ratio, cortical involvement, and mismatch sign. For IDH status and 1p/19q codeletion prediction, bootstrap-corrected areas under the receiver operating characteristic curve were 0.86 (95% CI: 0.81, 0.90) and 0.73 (95% CI: 0.65, 0.81), respectively, whereas at external validation they were 0.99 (95% CI: 0.98, 1.0) and 0.88 (95% CI: 0.63, 1.0). Conclusion The T2-FLAIR mismatch sign and scoring systems using standard clinical MRI predicted IDH and 1p/19q codeletion status in gliomas lacking contrast enhancement. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Badve and Hodges in this issue.

On the Sensitivity of the Potential Evapotranspiration of Egypt to Different Initial Conditions of the Soil Moisture Using a High-resolution Regional Climate Model

The present study investigated the sensitivity of the Potential Evapotranspiration (PET) of Egypt to different initial conditions of soil moisture using a high-resolution Regional Climate Model (RegCM4). To address this issue, two 32-year simulations were conducted from 1979 to 2010. The first two years were considered as spin-up. In the first simulation, the RegCM4 was initialized with the satellite product ESACCI (ESA) and the RegCM4 was initialized with version 3 of the Century Reanalysis Product (CEN) in the second simulation. The PET was computed using a calibrated version of the Hargreaves–Samani (HS) equation. In the two simulations, the RegCM4 was configured with the Community Land Model version 4.5 (CLM45). Era-Interim Reanalysis of 1.5 degrees (EIN15) was used to downscale the RegCM4 with 25 km grid spacing. The ERA5-based product (ERA5) was used as the observational dataset. The results showed that switching between ESA and CEN didn’t induce a notable influence on the daily maximum air temperature. Regarding the daily minimum air temperature, the CEN outperforms the ESA concerning the Climate Research Unit (CRU). In comparison with the ERA5 product, the CEN was able to reduce the PET negative bias (0.8 to 1.8 mm day-1) better than the one noted in the ESA (0.8 to 3 mm day-1). On a point scale, the performance of the ESA/CEN varies with the location and month. Such a point was confirmed using different statistical metrics such as mean bias, Pearson correlation coefficient and standard deviation ratio. In conclusion, the CEN can be recommended to initialize the RegCM4 to ensure a reliable estimation of the PET of Egypt either in the present climate or under different future scenarios.

Predictive Service Provisioning With Online Learning in Wireless Edge Networks

Mobile Edge Computing (MEC) technology can be implemented at cellular base stations, enabling flexible and configurable provisions of services for mobile users to access. Nevertheless, the conventional solutions mainly focus on <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">statical</i> service provisioning, which ignores the dynamic nature of the arriving service requests. In this work, we first conduct comprehensive data-driven observations on over 4 million service requests throughout 9,800 base stations. Our key findings suggest that users' demands intrinsically exhibit spatial and temporal patterns, which inevitably lead to performance degradation in statical service provisioning. Motivated by that, we design and implement MobiEdge, a predictive service provisioning system with online learning in wireless edge networks. We propose a graph embedding learning-based model for representation learning, thus to achieve accurate request prediction at different base stations. Then, based on the prediction of incoming service requests, we study the service provisioning reconfiguration problem, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i.e.</i> , how to jointly optimize service placement and corresponding request scheduling across dual timescales, under constraints of network resources and the total budget. By leveraging the submodular technique, we transform the research issue into a submodular function maximization problem under the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$q$</tex-math></inline-formula> -independence system constraint, where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$q$</tex-math></inline-formula> is a positive constant related to the ratio of coefficients in constraint conditions. On this basis, we propose a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$1/(1+q)$</tex-math></inline-formula> approximation algorithm with rigorous theoretical analysis on the bounded maximum utility. Extensive trace-driven evaluations are conducted over networks of different scales, and MobiEdge shows remarkable performance enhancements by achieving the accuracy of up to 98% in service prediction and an average utility of 92.9% to the optimal solution in service provisioning.