Direct Factor Research Articles

Barrier-Augmented Lagrangian for GPU-based Elastodynamic Contact

We propose a GPU-based iterative method for accelerated elastodynamic simulation with the log-barrier-based contact model. While Newton's method is a conventional choice for solving the interior-point system, the presence of ill-conditioned log barriers often necessitates a direct solution at each linearized substep and costs substantial storage and computational overhead. Moreover, constraint sets that vary in each iteration present additional challenges in algorithm convergence. Our method employs a novel barrier-augmented Lagrangian method to improve system conditioning and solver efficiency by adaptively updating an augmentation constraint sets. This enables the utilization of a scalable, inexact Newton-PCG solver with sparse GPU storage, eliminating the need for direct factorization. We further enhance PCG convergence speed with a domain-decomposed warm start strategy based on an eigenvalue spectrum approximated through our in-time assembly. Demonstrating significant scalability improvements, our method makes simulations previously impractical on 128 GB of CPU memory feasible with only 8 GB of GPU memory and orders-of-magnitude faster. Additionally, our method adeptly handles stiff problems, surpassing the capabilities of existing GPU-based interior-point methods. Our results, validated across various complex collision scenarios involving intricate geometries and large deformations, highlight the exceptional performance of our approach.

LNG storage tanks 9% Ni steel weld inspection via phased-coherent TFM and SVD enhancement

ABSTRACT 9% Ni steel is commonly utilised in liquefied natural gas storage tanks due to its strong resistance to corrosion and oxidation. However, the welds in these tanks are prone to serious defects, necessitating thorough non-destructive testing. Unfortunately, when inspecting nickel-based alloy welds using phased array ultrasonic testing (PAUT) technology the ultrasonic waves are scattered and attenuated because of the coarse columnar grains. To address this challenge, this paper introduces a based on SVD enhancement directivity corrected circular coherence factor weighted TFM imaging algorithm (SVD-DC-CCF). Initially, the CCF matrix is corrected by the directivity and energy attenuation compensation factors, then weighted with the TFM pixel point amplitude. Subsequently, the weighted amplitude matrix undergoes singular value decomposition (SVD), followed by the establishment of an enhancement factor to reconstruct the amplitude matrix. The proposed algorithm is evaluated through experiments on three types of defects in a 30.0 mm thick 9% Ni steel T-shaped fillet weld test block. Results demonstrate superior signal-to-noise ratio (SNR) and enhanced image resolution. Compared to TFM results, the SNR increases by 4.97 dB, 4.25 dB, and 4.96 dB, respectively, while the array performance index (API) decreases by 9.80%, 34.39%, and 22.22%, respectively.

Seismic design parameters of double-layer diamatic domes

The effect of past earthquakes (e.g., the 1995 Kobe and 2016 Kumamoto earthquakes) on the space structures revealed the fact that the assumption of the invulnerability of these structures is incorrect despite their light self-weight and high degree of redundancy, and space structures may suffer severe damage during strong ground motions. Therefore, special attention should be paid to the design of this type of structure in high seismic-risk regions. Nevertheless, the existing seismic design codes have not provided the seismic design parameters (i.e., the seismic response modification factors), including the behavior factor, R, and the displacement amplification factor, Cd for space structures. This research aims to extract the seismic design parameters of double-layer diamatic domes (DLDDs) to answer the challenges that structural engineers face in the design of this type of structure. For this purpose, 16 DLDD models with different rise-to-span ratios (RSRs) and span lengths were considered. After designing the models and performing the nonlinear time history analysis using the simultaneous effect of the three transitional components of ground motions, the target displacement at the control node was determined. Then, the pushover analysis was carried out to derive the capacity curve of the structures and calculate the seismic response modification factors in both horizontal and vertical directions. The results indicate that the domes with RSRs of 1/7 and 1/5 should be designed such that they remain in the elastic state in the horizontal direction. Then, with the growth of RSR, the value of R increases and reaches 1.792. Finally, equations were presented in this study for the period, behavior factor, and displacement amplification factor of DLDD structures in both horizontal and vertical directions using the nonlinear regression analysis.

Entropy optimization in ternary hybrid nanofluid flow over a convectively heated bidirectional stretching sheet with Lorentz forces and viscous dissipation: A Cattaneo–Christov heat flux model

Bidirectional stretching sheet models can represent surfaces in heat exchangers where fluids flow under continuous deformation. Ternary hybrid nanofluids could be employed in these systems to increase heat transfer rates between fluids in heat exchangers and improve the efficiency of energy conversion processes. In this work, we explore the novel application of a ternary hybrid nanofluid (water with titanium dioxide, cobalt ferrite, and magnesium oxide nanoparticles) for enhanced heat transfer in heat exchangers modeled by a bidirectional stretching sheet. This approach offers a potential advancement over traditional nanofluids (with one or two nanoparticles). Furthermore, we present a comprehensive analysis that incorporates ohmic heating, Cattaneo–Christov heat flux, thermal radiation, viscous dissipation, and irreversibility. The governing equations are transformed into a system of nonlinear ordinary differential equations using appropriate similarity transformations and then solved using the bvp4c solver, a MATLAB built-in function. This study's findings reveal that the Eckert number and radiation parameter increase fluid temperature, while the thermal relaxation parameter leads to a reduction in the temperature of the fluid. It is detected that an increase in magnetic field parameter and volume fraction of [Formula: see text] results in a decline of the skin friction factors in both directions. It is revealed that there is a reduction in the Nusselt number with the rise in Eckert number ([Formula: see text]), and the same number declines at a rate of 0.8252 when [Formula: see text]. It is noticed that the skin friction coefficient declines at a rate of 0.62179204 (in case of x-direction) and 0.621791816 (in case of y-direction), respectively, when the values of magnetic field parameter lie between 0 and 3.5. Furthermore, it is noticed that an upsurge in thermal relaxation parameter results in a fall in the temperature of the fluid.

Rate-dependent constitutive model and dynamic response of composite laminates for laser-induced delamination

Laser Bond Inspection is a new technology to quantitatively evaluate the interfacial strength in composite materials. Constructing an effective constitutive model, especially considering strain rate effects, is a critical factor for this technology. In this work, a reliable rate-dependent constitutive model of composite laminates for laser-induced delamination is established. Based on an orthotropic constitutive relationship, we introduce dynamic increase factors in different directions to adjust constitutive parameters. The dynamic increase factors are obtained through an adaptive matching model based on deep transfer learning. Then we effectively determine material rate-dependent constitutive relationship and ultimately achieve numerical simulation of laser-shocked composite laminates. Combining empirical testing with numerical simulation results, we investigate the dynamic response law of composite laminates under different laser parameters. The findings indicate that the rate-dependent constitutive model, effectively describes the mechanical behavior and dynamic response characteristics of composite laminates under laser shock. The dynamic response characteristics are determined by laser energy, pulse width, and spot size. Both laser energy and spot size affect the range of delamination, and pulse width mainly affects the depth of delamination.

Business Leadership in E-Commerce in the USA: The Impact of Blockchain Technology

Due to the evolution of digital finance and the active development of cryptocurrencies, blockchain is no longer just a tool for cryptocurrency extraction or database management but a technology that has a wider range of benefits for every trader who wants to conduct transactions using electronic payment instruments (cost improvement, effective tracking and traceability, verifiable record-keeping, transparency, etc.). The impact of blockchain technology on e-commerce can be viewed through the prism of unprecedented technological capabilities, legal and regulatory issues, customer data analysis, the design of communication channels along the supply chain, and trust and security. The article investigates the effect and the direction of the impact made by changes in digital blockchain technologies on retail prices in US e-commerce during 2014-2023 based on the VECM error correction model (software package – Eviews 12). The stability of the time series of the studied variables was confirmed by the Phillips-Perron test, and the Granger causality test showed the absence of a causal relationship between the studied factors in both directions. Instead, the Johansen Juselius Joint Integration Test showed a long-term balance between the studied variables (this is what allows using the VECM model). The results of the delay test of the studied model by two criteria (AIC and SC) showed that the optimal number of delays for the studied variables is 2. When conducting validity tests of the VECM model (joint integration test, LM test, heterogeneity test, unit root test, etc.), it was found that the model does not suffer from the problem of heterogeneity or self-correlation and meets the stability conditions. The study results indicate a positive impact of changes caused by blockchain technology on e-commerce in the long run (changes in digital blockchain technology explain 44% of retail e-commerce changes), with no short-term effect. Any shock in retail e-commerce will quickly affect changes in digital blockchain technology and vice versa (from the first period).

Discovering the Essence of Problems from the Approach of “Outside the Game”

This paper discusses the challenges in identifying the true essence of economic and management problems due to their complexity and multifaceted nature. Decision-makers often mistake appearances for the underlying issues, leading to ineffective solutions. The authors argue for a deeper analysis that considers both direct and indirect factors, as well as the system’s equilibrium and disequilibrium states. They highlight the importance of understanding the system's structure and the role of seemingly insignificant factors in driving change. The paper uses the example of Saharan poverty to illustrate the need for addressing cultural and institutional roots rather than just economic measures. The authors call for an “outside the game” perspective to uncover the real causes and develop effective strategies for problem-solving.

Factors influencing proxy online health information seeking among the elderly: A study from the perspective of the elderly with chronic illnesses.

With the ageing population in China and an increasing number of the elderly developing chronic illnesses, health services for the elderly have become a major concern. They have significant needs for health information (HI) such as online medical consultation, disease prevention, and medical insurance. To explore the influencing factors and their relative significance in proxy online health information (OHI) seeking among the elderly with chronic illnesses so as to provide a reference for enriching theoretical research and optimizing care for the elderly with chronic illness. Twenty-three elderly people with chronic illnesses participated in semi-structured in-depth interviews in this study. The interview transcripts were subject to three levels of coding (open, axial, and selective coding) based on grounded theory to determine the factors influencing proxy OHI seeking among the elderly and to understand how the main categories are interconnected. We used the interpretive structural modeling (ISM) process to analyze the hierarchy and associated pathways among the factors influencing proxy OHI seeking. From our analysis, we identified four main categories affecting proxy HI seeking: the health status, emotional needs, electronic HI literacy, and self-efficacy of the elderly. There were six subcategories that could be further subclassified into direct factors, key factors, and root factors, which constituted the hierarchical model of influencing factors. We found that proxy HI seeking among the elderly was directly triggered by self-efficacy and emotional needs following changes in their evaluation of health information and emotional needs, which originates from their perceptions of their health, concerns about their health, and information retrieval capability.

Buying a Wealthy Dream: Determinants of Rural Residents' Lottery Purchase Behavior in China.

The expansion of illicit lottery activities has caused significant harm to both agricultural production and the livelihood of rural residents. An analysis of the factors that influence rural residents' participation in underground lotteries can provide crucial insight for regulating the lottery industry's development. This study examines the present state of rural residents' participation in underground lotteries, investigates the factors that impact their participation using the Double-Hurdle model, and further employs the ISM model to evaluate the correlations and hierarchical structure among the factors, using field survey data collected from 603 rural residents in S Province, China. The findings reveal that 53.07% of the respondents have participated in underground lotteries. Risk preference, information acquisition, social networks, age, education, family burden, percentage of agricultural labor, agricultural business scale, and household income significantly affect whether residents purchase lotteries (WPL). All factors, except the percentage of agricultural labor and agricultural business scale, also significantly impact underground lottery spending (LS). Among the significant influencing factors, rural residents' risk preference is the direct surface factor, whereas agricultural business scale, household income, information acquisition, and social networks are the middle indirect factors, and residents' age, education, family burden, and percentage of agricultural labor are the deep-rooted factors. It is recommended to regulate the lottery industry's development can be achieved by enhancing entertainment and cultural activities, expanding economic opportunities, enhancing rural education, increasing law awareness, and improving the public welfare lottery business model. The conclusions offer a valuable reference point for the standardized development of the lottery industry and the promotion of social stability in rural areas.

Direct and Indirect Factors Affecting the Forced Swim Test to Investigate the Level of Depression in Rodents

Context: The forced swim test (FST) is employed to examine depression and depressive-like behaviors in rodents, such as mice and rats. In this test, increased periods of immobility and decreased swimming by the animal indicate heightened despair and depression-like behaviors. Evidence Acquisition: This review discusses the impacts of the animals' race, gender, age, and weight and environmental factors like light, noise, and smell on the FST. Results: Our review reveals that racial differences in rats and mice can influence their behavior. Differences in the nervous system structure and sex hormones related to gender are also significant. Additionally, animals that are very young or old, and those that are either very overweight or underweight, are unsuitable for the FST. Environmental factors such as light, noise, and smell were identified as confounding factors that could influence the outcomes and compromise the study's reliability. Conclusions: It is essential to consider these factors and enhance the conditions and environment to carry out a standardized test. Furthermore, by acquiring more detailed information about these factors and minimizing or eliminating their effects, studies can yield more reliable results.

Venous thromboembolism - was is new in the revised AWMF guideline?

For the diagnosis of a lower-extremity deep vein thrombosis (LEDVT), venous duplex ultrasound is the method of first choice. If a qualified ultrasonography is not timely available, D-dimer testing, and limited ultrasound protocols (point-of-care ultrasound, POCUS) can contribute to therapeutic decision-making when clinical probability is low. A DOAC-based treatment regimen is preferable to a vitamin K antagonist for both acute therapy and secondary prophylaxis of venous thromboembolism (VTE). Treatment with DOACs is unproblematic up to a body weight (BW) of 120 kg or a body mass index (BMI) of 40 kg/m². Weight restrictions are no longer recommended for apixaban and rivaroxaban, but determination of DOAC trough and peak levels is recommended in the extremely obese and patients after bariatric surgery. In cancer-associated VTE, the direct factor Xa inhibitors are a good and safe alternative to low-molecular weight heparins (LMWH) for many patients; the adherence to oral therapy is also higher. Meaningful initial documentation and structured follow-up after LEDVT and pulmonary embolism (PE) are important in order to make an individualized risk-benefit assessment at the end of the therapy phase with regard to continued pharmacological secondary prophylaxis and to reassess patients' symptoms indicating post-thrombotic syndrome (PTS) or chronic thromboembolic pulmonary hypertension (CTEPH).

Extreme climate and human activities contribute to low-frequency, large-scale catastrophic debris flow: a case study in the Heishui Gully

Rainfall is an excitation factor for rainfall-type debris flows, and high-frequency rainfall commonly does not directly trigger large-scale catastrophic debris flows. A low-frequency, large-scale catastrophic debris flow occurred in Heishui Gully (HSG), Pingwu County, Sichuan Province, southwestern China on 12 July 2022. In this study, the HSG debris flow was used as a case study to reveal the formation mechanisms of low-frequency and large-scale catastrophic debris flow triggered by high-frequency gentle rainfall by calculating and analysing a total of five indicators, including the Standard Precipitation Index (SPI), the Freeze-Thaw Index (FTI), the empirical relationship between earthquakes and landslides, the hypsometric integral (HI) and human activities. The study results indicate that high-frequency gentle rainfall is a direct factor in the debris flow outbreak in HSG. Long-duration extreme drought conditions and extreme freeze-thaw erosion provided sufficient soil conditions for debris flow formation. Frequent earthquakes and mature erosional geomorphologic evolution have indirectly contributed to the debris flow formation. Simultaneously, human activities downstream of HSG amplified the risk of debris flow disaster. The results reveal the contribution of extreme climates and human activities to low-frequency, large-scale catastrophic debris flows initiated by high-frequency gentle rainfall, which is significant for accurately assessing and predicting debris flow occurrence.

Investigating the individual interests of undergraduate students in STEM disciplines

Despite massive investments in the education sector to empower youth in Qatar, a vital concern remains to retain students in science, technology, engineering, and mathematics (STEM) disciplines at the undergraduate level. Even though the country is committed to fostering a knowledge-based society, the low interest of undergraduates in STEM disciplines remains a vital challenge. To investigate this, the current study uses a survey methodology to investigate the perspectives of 172 undergraduate students to understand quantitatively the factors that influence their individual interests in STEM disciplines. Non-parametric significance tests and binary logistic regressions were employed to quantitatively measure the direct factors and predictors that affect students’ individual interests. Findings indicated that aspects like students’ reason/motivation to join STEM, their interaction with faculty, the habit of skipping classes, the difficulty faced in the curriculum, and their parents’ highest educational qualification have an association with individual interests. Also, it was found that demographics such as age group, ethnicity, undergraduate discipline, undergraduate year, parent’s employment status, and mother’s highest educational qualification do not contribute to significant differences in students’ individual interests. These conclusions provide important implications for educationists and policymakers to devise constructive reforms to enhance undergraduate students’ individual interests, thereby improving their persistence in STEM.

Exposition and Slope Relief Indicators of the Tovuzchay-Esrikchay Rivers Basin

The Tovuzchay basin, located on the northeastern slope of the Lesser Caucasus, is surrounded by the Kura River from the north, the Agstafachay basin from the west and the Zayamchay basin from the east. The relief of the basin has an ancient history of development and was formed under the influence of endodynamic processes together with the geological structure. The relief, geological and geomorphological structure of the area were studied in detail by V. Khain, Sh. Azizbekov, L. Leontiev, M. Kashgai and other researchers. Relief plays an important role in determining the direction of land use as the main component of ecosystems and geosystems, and also has a significant impact on human economic activity. The study of relief slope, degree of fragmentation, slope direction, slope and other factors is a morphometric analysis of the terrain, and plasticity maps based on them serve as the basis for agroecological assessment of lands.

Hubungan Faktor Sanitasi, Ibu, dan Ekonomi Keluarga dengan Kejadian Stunting pada Balita di Puskesmas Sungai Tering Kabupaten Tanjung Jabung Timur

Stunting can be caused by direct and indirect factors. The aim of the study was to determine the factors associated with the incidence of stunting in toddlers in the working area of the Sungai Tering Public Health Center, East Tanjung Jabung Regency.The type of the research is cross sectional study. Data was collected in the working area of the Sungai Tering Community Health Center, East Tanjung Jabung Regency, with a total sample of 157 toddlers aged 24-59 months. The variables studied are environmental sanitation, maternal, and family economy factor. Stunting was measured by TB/U (Height-for-age) < -2 SD, Chi-Square analysis and logistic regression.The proportion of stunting under five is 26.1%. There is a relationship between enviromental sanitation that is house conditions, mother factor that are knowledge and parity with stunting. There is no correlation between economics factor with stunting. The dominant factor is the age of the mother during pregnancy who was relatively young (<20 years) (POR 6.04; 95% CI 0.77-47.19) after controlling for the variables of clean water facilities, house conditions, mother's knowledge, age of first mother married, parity , spacing of pregnancies, and family income. Maternal age during pregnancy <20 is the dominant factor causing the risk of stunting. It is recommended that people avoid early marriage and if it has already happened, it is best to postpone pregnancy with contraception until the ideal gestational age is > 20 - < 35 years.

Finite normal subgroups of strongly verbally closed groups

Abstract In a recent paper by A. A. Klyachko, V. Y. Miroshnichenko, and A. Y. Olshanskii, it is proven that the center of any finite strongly verbally closed group is a direct factor. In this paper, we extend this result to the case of finite normal subgroups of any strongly verbally closed group. It follows that finitely generated nilpotent groups with nonabelian torsion subgroups are not strongly verbally closed.

Explosive field trial for repetitive testing of VBIEDs to probabilistically measure blast and fragmentation hazards

This paper describes results from an explosive field trial of the detonation of Vehicle-Borne Improvised Explosive Devices (VBIEDs). The purpose of the trials is to replicate tests with identical car type and explosive mass to help probabilistically characterise the uncertainty and variability of blast pressures and fragment hazards. These variabilities may be considerable, and it is important to recognise that the world is not deterministic. The paper describes the spatial variability (directionality) of incident pressure, impulse and time of positive phase duration, and compares these to results from a bare charge, and the hemispherical surface burst Kingery and Bulmash polynomials often used for predicting blast loads from IEDs, such as ConWep. This also allows directional airblast factors to be quantified. The spatial distribution of over 26,000 fragments on the ground is also presented over the 250 m × 300 m test arena. The fragment densities and velocities obtained from the witness panels are also described, and preliminary fatality risks were estimated. These data may help develop or validate airblast and fragment hazard numerical or other models. Ultimately, probabilistic approaches will provide decision support for the determination of safety distance and risk reduction measures to prevent fatality and injury from blast pressure and fragmentation hazards.

Lineage-determining transcription factor-driven promoters regulate cell type-specific macrophage gene expression.

Mammalian promoters consist of multifarious elements, which make them unique and support the selection of the proper transcript variants required under diverse conditions in distinct cell types. However, their direct DNA-transcription factor (TF) interactions are mostly unidentified. Murine bone marrow-derived macrophages (BMDMs) are a widely used model for studying gene expression regulation. Thus, this model serves as a rich source of various next-generation sequencing data sets, including a large number of TF cistromes. By processing and integrating the available cistromic, epigenomicand transcriptomic data from BMDMs, we characterized the macrophage-specific direct DNA-TF interactions, with a particular emphasis on those specific for promoters. Whilst active promoters are enriched for certain types of typically methylatable elements, more than half of them contain non-methylatable and prototypically promoter-distal elements. In addition, circa 14% of promoters-including that of Csf1r-are composed exclusively of 'distal' elements that provide cell type-specific gene regulation by specialized TFs. Similar to CG-rich promoters, these also contain methylatable CG sites that are demethylated in a significant portion and show high polymerase activity. We conclude that this unusual class of promoters regulates cell type-specific gene expression in macrophages, and such a mechanism might exist in other cell types too.

Industrial Building Structure Planning With Cranes

Industrial building structure planning complies with standards and regulations, such as Procedures for Earthquake Resistance Planning, Minimum Loads for Building Design, and Specifications for Structural Steel Buildings. Vertical and lateral loads are fundamental to the structure's load flow process. Industrial buildings handle roof, wind, earthquakes, crane, and wall loads. Structural design must consider these elements, including the choice of lateral force-resisting systems such as X-bracing. In determining building loads, including earthquake and wind loads, various parameters such as wind speed, exposure category, and other factors must be considered by standard requirements such as SNI 1727-2020 and SNI 1726:2019. Selection of site class, wind direction, topographic, and ground surface elevation factors are essential in determining wind loads. This research method focuses on supporting structures consisting of purlins and girts in the context of industrial buildings. Purlins, made from hot or cold rolled steel, generally use C and Z profiles. Girts, made from cold or hot rolled steel, have profile variations such as C, Z, or hollow square sections. The girt structure design process determines dimensions, rod sag, internal requirements, and sag rod capacity.

The causal effect of triglyceride and high blood pressure on IgA nephropathy: a Mendelian randomization study.

It has been reported that high blood pressure (HBP) and triglyceride (TG) are considered risk factors in immunoglobulin A nephropathy (IgAN). This study aimed to explore the causalities between HBP and TG, and IgAN on the basis of Mendelian randomization (MR) analysis. Firstly, the genome-wide association study (GWAS) summary data of IgAN (GCST90018866) and two exposure factors, TG (ukb-d-30870_raw) and HBP (ukb-a-437), were sourced from the GWAS Catalog and Integrative Epidemiology Unit (IEU) OpenGWAS databases, respectively. In this study, five methods were utilized to perform MR analysis after picking out single nucleotide polymorphisms (SNPs) as instrumental variables, including MR-Egger, weighted median, simple mode, weighted mode, and inverse variance weighted (IVW), followed by the sensitivity analysis containing the heterogeneity, horizontal pleiotropy test and leave-one-out (LOO) analysis. Finally, the enrichment analysis and interaction network construction of genes corresponding to SNPs of HBP and TG were performed. The univariate MR results revealed that HBP and TG regarded as risk factors were causally related to IgAN [TG: p = 0.046, odds ratio (OR) = 1.065, 95% confidence interval (CI) = 1.001-1.133; HBP: p = 7.09 × 10-7, OR = 1.970, 95% CI = 1.507-2.575] based on random-effect IVM method, of which TG had a weaker impact. The reliability of these univariate MR results was certified by the sensitivity analysis, in which there was no horizontal pleiotropy and exaggerated influence of each SNP. Furthermore, HBP was markedly causally related to IgAN (p = 0.000512) with the help of multivariate MR analysis, rather than TG (p = 0.332). Therefore, when HBP and TG occur simultaneously, HBP is a direct influencing factor on IgAN. Ultimately, a total of 208 and 153 genes separately corresponding to SNPs of TG and HBP were included in enrichment analysis, and thereinto, genes relevant to TG were mainly enriched in lipid homeostasis and cholesterol metabolism, while genes concerned with HBP played their roles in regulation of cell growth, aldosterone synthesis and secretion and so forth. TG and HBP as risk factors were causally connected with IgAN, of which HBP was strongly related to the onset of IgAN, providing more reliable evidence for further exploring the relationship between TG and HBP and IgAN.