Static Factor Research Articles

Simulation of bi-directional pedestrian flow in corridor based on direction fuzzy visual field

Bi-directional pedestrian flow in corridors is a complex dynamic system due to the diversity in pedestrian psychological characteristics. Incorporating individual differences of pedestrians is vital for improving pedestrian flow models. However, due to the inherent complexity and variability of pedestrian movement, model parameter calibration remains challenging. Controlled experiments are needed to collect empirical pedestrian movement data under different environments. This enriches the database on pedestrian movement patterns and provides necessary support for improving pedestrian flow models. To address this issue, we conducted controlled experiments to quantify pedestrian heterogeneity by defining the direction of fuzzy visual field (DFVF). The DFVF incorporates various static and dynamic pedestrian factors. We used it to modify the traditional cellular automata model. This improved model simulates bi-directional pedestrian movements in the corridors, reproduces density-speed and density-volume relationships, and reveals self-organization phenomena. Furthermore, an analysis was conducted to examine the impacts of pedestrian density and facility spatial layout on evacuation time. Pedestrian interactions were also studied to uncover fundamental bi-directional flow properties. As pedestrian density increased, the evacuation time showed an exponential upward trend. Corridor length significantly impacts evacuation time, while increasing corridor width helps control it. As crowd density increases, pedestrian flows exhibit three distinct steady states: the strolling flow at low densities, directional separated flows at medium densities, and dynamic multi-lane flows at high densities. In summary, the modified cellular automata model successfully incorporates pedestrian heterogeneity and reveals intrinsic bi-directional pedestrian flow patterns. This study provides valuable insights for pedestrian facility design and optimizing pedestrian flow organization.

Abstract 12785: Abnormal Dynamic Remodeling of the 12-Lead Electrocardiogram is a Risk Marker for Sudden Cardiac Death

Introduction: The ECG has always been evaluated as static risk factor for sudden cardiac death (SCD). The importance of dynamic ECG remodeling has not been investigated. Hypothesis: Abnormal ECG remodeling over time is associated with increased risk of SCD. Methods: We investigated pre-SCD ECG remodeling in SCD cases from 2 ongoing population-based studies of out-of-hospital SCD in Portland, OR (discovery) and Ventura County, CA (validation). Two archived pre-SCD ECGs performed at least 1 year apart were obtained from lifetime health records. Controls were matched on geographical region, age, sex, and duration between the 2 ECG recordings. Dynamic ECG remodeling was measured as the change in a previously validated cumulative 6-variable ECG electrical risk score (ERS) between the 1st and 2nd ECG. Results: A total of 231 SCD cases (66.5±13.6 years, 61% male), and 234 controls (65.8±11.1 years, 61% male) were included in the discovery cohort, and 203 SCD cases (70.3±14.4 years, 54% male), and 203 controls (68.4±11.8 years, 54% male) in the validation cohort. The mean time between the 2 ECG recordings in SCD cases and controls was 6.0±4.0 years vs 6.2±4.5 years (discovery) and 3.7±2.6 years vs. 3.7±1.6 years (validation), respectively. In both cohorts, SCD cases compared to controls had greater dynamic ECG remodeling over time: Discovery cohort ERS change +1.06 (95% CI +0.89 to +1.24) vs. -0.05 (-0.21 to +0.11; p<0.001) and validation cohort ERS change +0.87 (+0.7 to +1.04) vs. -0.11 (-0.27 to 0.05; p<0.001). In a multivariate model including clinical SCD risk factors, a 1-unit increase in the ERS was an independent risk marker for SCD: Discovery cohort OR 1.89 (95% CI 1.58-2.26; p<0.001), validation cohort OR 2.17 (95% CI 1.63-2.91; p<0.001). Conclusions: SCD cases were observed to have abnormal dynamic ECG remodeling prior to the SCD event, not observed in matched controls. These findings warrant further investigation of dynamic ECG remodeling as a novel risk marker for SCD.

Static and dynamic factors underlying placement instability in residential youth care: A scoping review

Placement instability in residential youth care is an important issue. Youth in residential care have the highest number of previous placements compared to youth in other types of out-of-home care (e.g., foster care), and the high number of previous placements can be experienced as traumatic events. Placement instability is associated with negative outcomes for youth, such as mental health problems. However, there is no review of the factors associated with placement instability in residential care. In this study, we reviewed research (qualitative and quantitative) on factors related to placement instability in residential youth care. A search in four databases (PsycINFO, ERIC, SocINDEX, and Medline) resulted in 10,299 hits. After selecting on the inclusion criteria, we included fifteen articles in our analysis. We identified several youth, family, decision-making, care, and, organizational factors associated with placement instability in residential care. In general, the number of studies focusing on placement instability is small. Most studies focused on static (i.e., unchangeable) youth factors, such as sex and age. We found some indications that dynamic (i.e., changeable) family, care, and organizational factors, such as poor parenting skills, low staff competence and turnover of professionals are positively associated with placement instability. It is striking that most of the included studies focused mainly on static youth factors. We need more knowledge about dynamic factors to reduce placement instability in residential youth care. Future research should focus on elements that might prevent placement instability.

Safety Analysis of Fastening Device of Agricultural By-Product Collector in Various Ground Conditions

In this study, to evaluate the safety of the fastening device, which is a vulnerable part of the agricultural by-product collector, the stress in fastening devices was measured, and the operational and driving safety were analyzed by deriving the static safety factor and fatigue life. The position with the maximum stress in fastening devices was identified through structural analysis simulation, and a stress measurement system was constructed using strain gauges. Test conditions for stress measurement were classified into three operating conditions (collection operation, driving with the loading part lifted to the highest point, and driving with the loading part lifted to the lowest point) and three soil conditions (even pavement, sloped pavement, and farmland). A process for deriving the fatigue life based on the measured stress was constructed by applying the rain-flow counting method, Goodman equation, and Palmgren–Miner’s rule via commercial software. From the stress measurement results, the collection operation exhibited the highest maximum stress, followed by driving with the loading part lifted to the highest point and driving with the loading part lifted to the lowest point. Under all conditions, the static safety factor of the fastening devices was found to be higher than 1.0 (1.16–1.33). The fatigue life of the fastening devices was also found to be longer than the service life of Korean agricultural machinery under all operating conditions. Therefore, the fastening devices are expected to operate safely under generated static and dynamic loads. The agricultural by-product collector can perform agricultural work and drive stably and is expected to contribute to reducing unnecessary labor force for Korean farms.

From lagging behind to going beyond: windows of opportunity and latecomers' catch-up strategies

PurposeTo answer the questions: what roles windows of opportunity act in the catchup process of latecomers, what strategies latecomer enterprises should adopt to size windows of opportunity to catch-up with incumbents even going beyond?Design/methodology/approachThis paper studies the catch-up history of the Chinese mobile phone industry and proposes a sectoral innovation system under scenario of technology paradigm shifts. Then a history-friendly simulation model and counterfactual analysis are conducted to learn how different windows of opportunity and catch-up strategies influence the catch-up performance of latecomers.FindingsResults show latecomers can catch up with technology ability by utilizing technology window and path-creating strategy. However, catching up with the market is not guaranteed. Demand window can help latecomers to catch up with market as it increases their survival rates, different sized windows benefit different strategies. However, it also enlarges incumbents' scale effect. Without technology window technology catch up is not guaranteed. Two windows have combination effects. Demand window affects the “degree” of change in survival rates, while the technology window affects the “speed” of change. Demand window provides security; technology window provides the possibility of a breakthrough for technology ability.Practical implicationsThe findings of this paper provide theoretical guidance for latecomer enterprises to choose appropriate catch-up strategies to seize different opportunity windows.Originality/valueThis paper emphasizes the abrupt change of industrial innovation system caused by technology paradigm shifts, which makes up for the shortcomings of previous researches on industrial innovation system which either studied the influence of static factors or based on the influence of continuous changes.

Mechanism of RhoA regulating benign prostatic hyperplasia: RhoA-ROCK-β-catenin signaling axis and static & dynamic dual roles

BackgroundThe pathogenesis of benign prostatic hyperplasia (BPH) has not been fully elucidated. Ras homology family member A (RhoA) plays an important role in regulating cell cytoskeleton, growth and fibrosis. The role of RhoA in BPH remains unclear.MethodsThis study aimed to clarify the expression, functional activity and mechanism of RhoA in BPH. Human prostate tissues, human prostate cell lines, BPH rat model were used. Cell models of RhoA knockdown and overexpression were generated. Immunofluorescence staining, quantitative real time PCR (qRT-PCR), Western blotting, cell counting kit-8 (CCK-8), flow cytometry, phalloidine staining, organ bath study, gel contraction assay, protein stability analysis, isolation and extraction of nuclear protein and cytoplasmic protein were performed.ResultsIn this study we found that RhoA was localized in prostate stroma and epithelial compartments and was up-regulated in both BPH patients and BPH rats. Functionally, RhoA knockdown induced cell apoptosis and inhibited cell proliferation, fibrosis, epithelial-mesenchymal transformation (EMT) and contraction. Consistently, overexpression of RhoA reversed all aforementioned processes. More importantly, we found that β-catenin and the downstream of Wnt/β-catenin signaling, including C-MYC, Survivin and Snail were up-regulated in BPH rats. Downregulation of RhoA significantly reduced the expression of these proteins. Rho kinase inhibitor Y-27632 also down-regulated β-catenin protein in a concentration-dependent manner. However, overexpression of β-catenin did not affect RhoA-ROCK levels, suggesting that β-catenin was the downstream of RhoA-ROCK regulation. Further data suggested that RhoA increased nuclear translocation of β-catenin and up-regulated β-catenin expression by inhibiting its proteasomal degradation, thereby activating Wnt/β-catenin signaling. Overexpression of β-catenin partially reversed the changes in cell growth, fibrosis and EMT except cell contraction caused by RhoA downregulation. Finally, Y-27632 partially reversed prostatic hyperplasia in vivo, further suggesting the potential of RhoA-ROCK signaling in BPH treatment.ConclusionOur novel data demonstrated that RhoA regulated both static and dynamic factors of BPH, RhoA-ROCK-β-catenin signaling axis played an important role in the development of BPH and might provide more possibilities for the formulation of subsequent clinical treatment strategies.

The Role of Psychopathic Traits and Supportive Parental Practices in Long-Term Juvenile Recidivism: a 10-Year Follow-Up

Recidivism rates of juvenile delinquents remain high despite numerous intervention efforts. Identifying factors that can predict (long-term) recidivism is therefore an important research issue. Knowledge on why juveniles re-offend is a key to effective interventions as it helps to identify factors most likely to be successful targets in intervention programs. A 10-year follow-up study prospectively examined whether psychopathic traits and supportive parental practices predicted the timing and frequency of recidivism in juvenile delinquents. Participants were 256 adolescents who were referred to treatment for serious antisocial behavior (72.4% male). Participants were between 12 and 18 years old at baseline (M = 15.9 years). Parents reported on juveniles’ psychopathic traits and supportive parental practices at baseline. At 10-year follow-up, the official recidivism data were collected. A substantial number of juveniles (86.3%) had recidivated at 10-year follow-up. Juvenile psychopathic traits and supportive parental practices did not incrementally predict the timing or frequency of recidivism over time over and beyond the static control variables gender and prior offenses. The present study confirms previous work suggesting that static risk factors gender and prior offenses are strongest predictors of recidivism.

Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

With increasing drilling depth and large dosage of weighting materials, drilling fluids with high solid content are characterized by poor stability, high viscosity, large water loss, and thick mud cake, easier leading to reservoir damage and wellbore instability. In this paper, micronized barite (MB) was modified (mMB) by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite partly. The suspension stability of water-based drilling fluids (WBDFs) weighted with API barite:mMB = 2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs, exhibiting the static sag factor within 0.54 and the whole stability index of 2. The viscosity and yield point reached the minimum, with a reduction of more than 40% compared with API barite only at the same density. Through multi-stage filling and dense accumulation of weighting materials and clays, filtration loss was decreased, mud cake quality was improved, and simultaneously it had great reservoir protection performance, and the permeability recovery rate reached 87%. In addition, it also effectively improved the lubricity of WBDFs. The sticking coefficient of mud cake was reduced by 53.4%, and the friction coefficient was 0.2603. Therefore, mMB can serve as a versatile additive to control the density, rheology, filtration, and stability of WBDFs weighted with API barite, thus regulating comprehensive performance and achieving reservoir protection capacity. This work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

The Effects of Undercut Depth and Length on Weldment Mechanical Properties

Undercutting is a fusion welding defect that appears as a groove at the weld metal's toe. An undercut discontinuity forms when welding, particularly when the current is applied at an extremely rapid rate. It decreases the static and fatigue strength of the weld and produces stress concentration at the welding zone. The height of the reinforcement, the weld bead's contact angle, the undercut's breadth, depth, length, and root radius, as well as other factors, affect the stress concentration factor's size. In this study, two mild steel plates with a 20 mm thickness were welded together using gas metal arc welding. Each test plate was machined to have a 30° single bevel groove angle prior to welding. The butt welded plate underwent radiographic NDT testing. A weldment free of defect was created. The weldment was machined into typical test specimens for tensile strength. An undercut defect was simulated by drilling a groove through each tensile test sample. Grooves had different depths and lengths. After that, samples were put through a tensile test. The test findings allowed for the identification of the impacts of groove shape on tensile strength, ductility, and static stress concentration factor.

Alcohol Consumption and Violent Offending: Findings From a Longitudinal Study on Korean Youth from Mid to Late Adolescence

Although past research highlights a close relationship between alcohol and crime, its role as a static (i.e., stable) and dynamic (i.e., changing) risk factor of violent delinquency has been less studied. Cross-lagged dynamic panel models were employed to address this issue based on a longitudinal Korean adolescent sample. Despite the significant independent effects of baseline individual differences in alcohol use, its impact on violence was no longer statistically significant when accounting for within-individual changes in alcohol consumption. However, we also found interaction effects between baseline and within-individual changes in alcohol consumption; youth who consume more alcohol at earlier ages and engage in more alcohol use over time are more likely to engage in violence. Findings stress the importance of studying static and dynamic factors and their interaction to provide a greater understanding of violent delinquency. Limitations and implications for policy and practices are discussed.

Determination of Stress Concentration Factor for a Stepped Bar Under Bending Loading: An Artificial Neural Networks Approach

Even today, charts and formulas derived from experimental determinations are used to obtain the stress concentration factor.Stress concentration factors from charts can be converted into numerical values using computational techniques. Stress concentration factor values were collected in a database and an Artificial Neural Network (ANN) model can be developed for improving the database. ANN model provides accuracy in obtaining the stress concentration factors. Using the static stress concentration factor for a stepped bar under a bending load we can quantify the impact of notches in fatigue.

Driving Mechanisms of Spatiotemporal Heterogeneity of Land Use Conflicts and Simulation under Multiple Scenarios in Dongting Lake Area

As an important ecological hinterland in Hunan Province, the Dongting Lake area has an irreplaceable role in regional socioeconomic development. However, owing to rapid environmental changes and complex land use relationships, land use/land cover (LULC) changes are actively occurring in the region. Therefore, assessment of the current LULC status and the future development trend for sustainable economic development is of considerable importance. In this study, the driving mechanisms of spatiotemporal evolution for land use conflicts (LUCF) in Dongting Lake from 2000 to 2020 were analyzed by constructing a LUCF model. Additionally, a new model, EnKF-PLUS, which couples ensemble Kalman filtering (EnKF) with patch-generating land use simulation (PLUS), was developed to predict the LULC changes and LUCF in 2030 under different scenarios. The results provide three insights. First, during the period of 2000–2020, high LUCF values were concentrated in highly urbanized and densely populated areas, whereas low LUCF values were centered in hilly regions. Secondly, the impacts of static factors (topographical factors) and dynamic factors (population, GDP, and climate factors) on changes in LUCF were regionally differentiated. Thirdly, our results indicate that the implementation of land use strategies of cropland conservation and ecological conservation can effectively mitigate the degree of LUCF changes in the region and contribute to the promotion of the rational allocation of land resources.

Higher baseline emotion dysregulation predicts treatment dropout in outpatients with borderline personality disorder.

Treatment dropout is high among outpatients with borderline personality disorder (BPD) and is associated with myriad negative therapeutic and psychosocial outcomes. Identifying predictors of treatment dropout can inform treatment provision for this population. The present study investigated whether symptom profiles of static and dynamic factors could predict treatment dropout. Treatment-seeking outpatients with BPD (N = 102) completed pre-treatment measures of BPD symptom severity, emotion dysregulation, impulsivity, motivation, self-harm, and attachment style to determine their collective impact on dropout prior to 6 months of treatment. Discriminant function analysis was used to classify group membership (treatment dropout vs. nondropout) but did not produce a statistically significant function. Groups were distinguished by baseline levels of emotion dysregulation with higher dysregulation predicting premature treatment dropout. Clinicians working with outpatients with BPD might benefit from optimizing emotion regulation and distress tolerance strategies earlier in treatment to reduce premature dropout. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

大葱种子物性参数测量及 DEM参数仿真标定

The contact parameters setting determines the accuracy of discrete element method (DEM) simulation analysis, while there is a lack of research on contact parameters of green onion seed. In this paper, the physical parameters of green onion seeds were measured by experiment, and the DEM parameters were calibrated by simulation. Based on EDEM software, the Hertz-Mindlin no-slip model was used to create the particle model of green onion seeds that takes on the shape of peltate with the irregular surface, and the repose angle was measured by the measurement method of lifted cylinder. Plackett-Burman test was designed to screen the significance of parameters, and the optimal range of significance parameters was further determined through the steepest climbing test. Then the regression model of seeds repose angle was obtained by Box-Behnken test and the optimal parameter combination was calculated: the static friction factor between seeds was 0.424, the rolling friction factor was 0.085, the static friction factor between seeds and steel was 0.310. The optimized repose angle in the simulation had an overall relative error of 0.54%, indicating that the contact parameters of the calibrated green onion seed had high accuracy.

Multiplane full-color phase-only holograms generation based on iterative algorithm with a modified amplitude constraint

Depth-division multiplexing (DDM) is distinguished for generating full-color holograms. However, this method is confronted with such issues as poor quality and severe crosstalk when reconstructing multiplane color images. In this paper, we propose an improved iterative method based on Gerchberg-Saxton (GS) algorithm to generate multiplane full-color phase-only holograms (POHs), and the information of red (R), green (G), and blue (B) channels of images is recorded in three POHs, respectively. In the iterative process, we introduce an improved hologram plane constraint that consists of modified amplitudes given a static weighting factor, and display the reconstruction results for three-layer images, which ultimately improve the quality of the reconstructed images and effectively avoid the crosstalk among different color channels. And compared with GS algorithm, our method can effectively balance the reconstruction quality of three-color channels of each image. The feasibility of the method is verified by numerical simulations and optical experiments.

Ab initio calculated dynamic structural factors and optical properties of beryllium along the Hugoniot

Beryllium is an ablator material used in inertial-confinement fusion and hypervelocity impact studies. The thermoelastic properties, structural factors, and optical properties of beryllium are important in these studies. In this paper, the static structural factors, ion–ion dynamic structural factors, adiabatic velocity, and optical properties of beryllium along the Hugoniot were calculated by ab initio simulations. The static structural factors show that beryllium atoms were randomly distributed. The dynamic structural factors extracted the dispersion relation for collective excitation via the scattering function. By collecting the peak position of the dynamic structural factors, the dispersion relation and adiabatic sound velocity were derived by definition. Using the calculated equation of state, the thermoelastic properties and adiabatic sound velocity have been derived. The two calculated methods for adiabatic sound velocity were verified to be equivalent.

공공기관 문화예술 콘텐츠의 서비스 품질이 관람 만족도에 미치는 영향

In this study, after subdividing their service quality factors around cultural and artistic contents of public institutions, we investigated which service quality factors are the main factors that lead to public satisfaction with viewing public cultural content, and the moderating effect of viewing frequency. As a result of the study, first, the difference in viewing satisfaction according to the final academic background of the study subjects and the frequency of visits to the culture and arts center was significant. Second, all of the service quality factors of cultural and artistic content were acting as static influencing factors of viewing satisfaction, and among them, tangible was the strongest static influencing factor. Third, it was found that there was no moderating effect according to the individual cultural and artistic involvement of the public. This researcher suggested that the tangible quality elements of the culture and arts center need to be improved first to improve the quality of culture and arts content in public institutions today.

A unified local-nonlocal integral formulation for dynamic stability of FG porous viscoelastic Timoshenko beams resting on nonlocal Winkler-Pasternak foundation

We present a study on the nonlocal dynamic stability of functionally graded (FG) porous viscoelastic Timoshenko beams resting on a Winkler-Pasternak foundation. The porosity distributions are assumed to be symmetric or antisymmetric about the mid-plane of the beams, and the Kelvin-Voigt viscoelastic model is considered to depict the beams’ viscoelastic properties. Unlike most studies on this topic, we consider both the beam’s bending deformation and the foundation reaction as nonlocal, simultaneously, by uniting the equivalently differential forms of two well-posed local-nonlocal integral models (i.e., strain-driven (ε-D) and stress-driven (σ-D) strategies) which are strictly equipped with a set of constitutive constraint conditions, through which both the softening and hardening effects on the stiffness of structures due to size reduction can be addressed. The generalized differential quadrature method (GDQM) is utilized for discretizing variables presented in the differential problem formulation, from which the numerical solution of the dynamic instability region (DIR) of different bounded beams can be obtained. After conducting comparative studies to validate the proposed model, the effects of nonlocal parameters, static force factor, porosity distribution and viscoelastic property on the DIR are investigated. Moreover, the influence of incorporating the nonlocality of the foundation is also presented.

Numerical investigation of the main factors influencing rocking responses of shallow foundations

Several investigations have shown that structures with rocking foundations bring more stability and fewer instances of post-earthquake damage to superstructures by dissipating seismic energy within the underlying soils. Nevertheless, there are still obstacles to making this design philosophy a practical solution, including concerns about the residual settlements and rotations. In order to provide a better insight into the problem, the present paper investigates the performance of a simple structure with a rocking foundation, taking advantage of pushover and time history analyses. The finite-element method is applied for the study, and the numerical model has been validated using results from recent experimental research. Accordingly, the effect of a number of influential parameters involving the properties of soil, structure and ground motions is evaluated. The current research considers different static safety factors against soil shear strength failure, structure slenderness ratios, earthquake records and foundation embedment depths, and the response of the systems with rocking foundations has been elaborated using the results obtained. The contribution of the investigated parameters is pronounced in the main features of the rocking foundation performance, such as the system moment capacity and foundation deformations (settlement and rotation).

Drought vulnerability of central Sahel agrosystems: a modelling-approach based on magnitudes of changes and machine learning techniques

ABSTRACT Agricultural drought is a complex phenomenon with numerous consequences and negative implications for agriculture and food systems. The Sahel is frequently affected by severe droughts, leading to significant losses in agricultural yields. Consequently, assessing vulnerability to agricultural drought is essential for strengthening early warning systems. The aim of this study is to develop a new multivariate agricultural drought vulnerability index (MADVI) that combines static and dynamic factors extracted from satellite data. First, pixel temporal regression from 1981 to 2021 was applied to climatic and biophysical covariates to determine the gradients of trend magnitudes. Second, principal component analysis was applied to groups of factors that indicate the same type of vulnerability to configure the basic equation of vulnerability to agricultural drought. Then, random forest (RF), K-nearest neighbours (KNN), support vector machine (SVM) and naïve Bayes (NB) were used to predict drought vulnerability classes using the 28 factors as inputs and 708 pts of randomly distributed class labels. The results showed statistical agreement between the predicted MADVI spatial variability and the reference model (R=0.86 for RF) and its statistical relationships with the vulnerability subcomponents, with an R=0.73 with exposure to climate risk, R=0.64 with the socioeconomic sensitivity index, R=0.6 with the biophysical sensitivity index and a relatively weak correlation (R=0.21) with the physiographic sensitivity index. The overall vulnerability situation in the watershed is 21.8% extreme, 10% very high, 16.8% high, 27.7% moderate, 22.2% low and 1.5% relatively low considering the cartographic results of the predicted vulnerability classes with SVM having the best performance (accuracy=0.96, Kappa=0.95). The study is the first approach that uses the gradients of magnitudes of satellite covariate anomaly trends in multivariate modelling of vulnerability to agricultural drought. It can be easily scaled up across the Sahel region to improve early warning measures related to the impacts of agricultural drought.