Deep learning approaches to recover the plasma current density profile from the safety factor based on Grad–Shafranov solutions across multiple tokamaks

Many magnetohydrodynamic stability analyses require generation of a set of equilibria with a fixed safety factor q-profile while varying other plasma parameters.A neural network(NN)-based approach is investigated that facilitates such a process.Both multilayer perceptron(MLP)-based NN and convolutional neural network(CNN)models are trained to map the q-profile to the plasma current density J-profile,and vice versa,while satisfying the Grad–Shafranov radial force balance constraint.When the initial target models are trained,using a database of semianalytically constructed numerical equilibria,an initial CNN with one convolutional layer is found to perform better than an initial MLP model.In particular,a trained initial CNN model can also predict the q-or J-profile for experimental tokamak equilibria.The performance of both initial target models is further improved by fine-tuning the training database,i.e.by adding realistic experimental equilibria with Gaussian noise.The fine-tuned target models,referred to as fine-tuned MLP and fine-tuned CNN,well reproduce the target q-or J-profile across multiple tokamak devices.As an important application,these NN-based equilibrium profile convertors can be utilized to provide a good initial guess for iterative equilibrium solvers,where the desired input quantity is the safety factor instead of the plasma current density.

Efficacy and safety of dacomitinib as first-line treatment for advanced non-small cell lung cancer patients with epidermal growth factor receptor 21L858R mutation:A multicenter,case-series study in China

Objective:To provide real-world evidence for the application of first-line dacomitinib treatment for epidermal growth factor receptor(EGFR)21L858R mutant non-small cell lung cancer(NSCLC)patients in China and to explore the factors influencing the efficacy and safety.Methods:A longitudinal,consecutive case-series,multicenter study with mixed prospective and retrospective data was conducted.The primary endpoint was progression-free survival(PFS),and the secondary endpoints included duration of treatment(DOT),overall survival(OS),objective response rate(ORR),disease control rate(DCR)and safety.Results:A total of 155 EGFR 21L858R mutant patients treated with first-line dacomitinib were included.The median follow-up time for these patients was 20.4 months.Among 134 patients with evaluable lesions,the ORR was 70.9%and the DCR was 96.3%.The median PFS was 16.3[95%confidence interval(95%CI),13.7−18.9]months.Multivariate Cox regression analysis suggested that the baseline brain metastasis(BM)status[with vs.without BM:hazard ratio(HR),1.331;95%CI,0.720−2.458;P=0.361]and initial doses(45 mg vs.30 mg:HR,0.837;95%CI,0.427−1.641;P=0.604)did not significantly affect the median PFS.The median DOT was 21.0(95%CI,17.5−24.6)months and the median OS was not reached.Genetic tests were performed in 64 patients after progression,among whom 29(45.3%)patients developed the EGFR 20T790M mutation.In addition,among the 46 patients who discontinued dacomitinib treatment after progression,31(67.4%)patients received subsequent third-generation EGFR-tyrosine kinase inhibitors.The most common grade 3−4 adverse events were rash(10.4%),diarrhea(9.1%),stomatitis(7.1%)and paronychia(4.5%).The incidence of grade 3−4 rash was significantly higher in the 45 mg group than that in the 30 mg group(21.9%vs.7.5%,P=0.042).Conclusions:First-line dacomitinib treatment demonstrated promising efficacy and tolerable adverse events among EGFR 21L858R mutant NSCLC patients in China.

Influence Factors for Safety Full Heading of Machine-transplanted Rice Seedlings in Cool-warm Rice Area

[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilizer dosage and strategy of machine-transplanted seedlings on safety full heading of machine-transplanted seedlings were investigated. [Result] During mechanized rice production in coolwarm rice area, mid-early-maturing cold-resistant varieties with growth periods no longer than 180 d could selected, and seedling age could controlled within 30-35 d; and the total amount of pure nitrogen should be less than 300 kg/hm^2, and the proportion of nitrogen fertilizer applied in later stages should be properly reduced. [Conclusion] Under this condition, safety full heading of rice is ensured, and the target yield is realized.

Impact of Improving Design Factor over 0.72 on the Safety and Reliability of Gas Pipelines and Feasibility Justification

Many years experience of the operation of high stress (>72% specified minimum yield strength, SMYS) gas pipelines and statistical analysis results of pipeline incidents showed that the operating pipelines at stress levels over 72% SMYS have not presented problems in USA and Canada, and design factor does not control incidents or the safety of pipelines. Enhancing pipeline safety management level is most important for decreasing incident rate. The application history of higher design factors in the U.S and Canada was reviewed. And the effect of higher factors to the critical flaw size, puncture resistance, change of reliability with time, risk level and the arrest toughness requirements of pipeline were analyzed here. The comparison of pipeline failure rates and risk levels between two design factors (0.72 and 0.8) has shown that a change in design factor from 0.72 to 0.8 would bring little effect on failure rates and risk levels. On the basis of the analysis result, the application feasibility of design factor of 0.8 in China was discussed and the related suggestions were proposed. When an operator wishes to apply design factor 0.8 to gas pipeline, the following process is recommended: stress level of line pipe hydro test should be up to 100% SMYS, reliability and risk assessment at the design feasibility or conceptual stage should be conducted, Charpy impact energy should meet the need of pipeline crack arrest; and establish and execute risk based integrity management plan. The technology of pipeline steel metallurgy, line pipe fabrication and pipeline construction, and line pipe quality control level in China achieved tremendous progresses, and line pipe product standards and property indexes have come up to international advanced level. Furthermore, pipeline safety management has improved greatly in China. Consequently, the research for the feasibility of application of design factor of 0.8 in China has fundamental basis.

Comprehensive safety factor of roof in goaf underdeep high stress

The safety factor of roof under deep high stress is a quantitative index for evaluating roof stability.Based on the failure mode of surrounding rock of stope roof,the mechanics model of goaf roof is constructed,and the internal force of roof is deduced by the theory of hingeless arch.The calculation method of roof safety factor(K)under the environment of deep mining is proposed in view of compression failure and shear failure of roof.The calculation formulas of shear safety factor(K1),compression safety factor(K2)and comprehensive safety factor(K)of roof are given.The influence of stope span and roof thickness on roof stability is considered in this paper.The results show that when the roof thickness remains constant,the roof safety factor decreases with the increasing of the stope span;when the stope span remains constant,the roof safety factor increases with the increasing of the roof thickness.The deep mining example shows that when the stope span is 30 m and the roof thickness is 10 m,the roof comprehensive safety factor is 1.12,which indicates the roof is in a stable state.

Addressing Human Factors in Burnout and the Delivery of Healthcare: Quality & Safety Imperative of the Quadruple Aim

Human factors in the delivery of service are considered in many occupations of high impact on others such as airline industry and nuclear power industry, but not sufficiently in healthcare delivery. A common administrative framework of healthcare involves focus upon costs, quality and patient satisfaction (The Triple Aim). Many industries which support healthcare and healthcare administrators do not have firsthand knowledge of the complexities in delivering care. As a result, the experience and human factors of providing care are often overlooked at high level decision-making unless incorporated into the healthcare delivery framework, proposed as the fourth aim of The Quadruple Aim framework. Research is pointing to consequent negative effects on quality, safety, joy, meaning and sustainability of healthcare practice. High acute occupational stress and chronic occupational stress can cause direct and indirect effects on safety and quality of care. The biological, psychological and social consequences of burnout from excessive acute and chronic occupational stress are more of a threat to healthcare than commonly acknowledged. Patient safety, quality of care and clinician well-being are inextricably linked. This report will describe the process of transition from The Triple Aim to The Quadruple Aim administrative framework of healthcare delivery at the University of Rochester Medical Center. Developing the fourth aim of improving the experience of providing care, had high acceptability and aligned with other health system goals of optimization of safety, quality, and performance by applying a human factors/ergonomic (HFE) framework that considers human capabilities and human limitations. The goal of HFE is to fit the healthcare system to the human instead of the human to the healthcare system. Concepts include removal of extraneous cognitive load, using clinician neural resource (brain power) optimally for highest order decision making in patient care. An integrative model of patient safety and clinician wellbeing is a product of this effort.

Three-dimensional stability of landslides based on local safety factor

Unlike the limit equilibrium method(LEM), with which only the global safety factor of the landslide can be calculated, a local safety factor(LSF) method is proposed to evaluate the stability of different sections of a landslide in this paper. Based on three-dimensional(3D) numerical simulation results, the local safety factor is defined as the ratio of the shear strength of the soil at an element on the slip zone to the shear stress parallel to the sliding direction at that element. The global safety factor of the landslide is defined as the weighted average of all local safety factors based on the area of the slip surface. Some example analyses show that the results computed by the LSF method agree well with those calculated by the General Limit Equilibrium(GLE) method in two-dimensional(2D) models and the distribution of the LSF in the 3D slip zone is consistent with that indicated by the observed deformation pattern of an actual landslide in China.

Factor of safety of strain-softening slopes

Stability analysis of strain-softening slopes is carried out using the shear strength reduction method and Mohr-Coulomb model with degrading cohesion and friction angle.The e ffect of strain-softening behavior on the slope factor of safety is investigated by performing a series of analyses for various slope geometries and strength properties.Stability charts and equations are developed to estimate the factor of safety of strain-softe ning slopes from the results of traditional stability analysis based on perfectly-plastic behavior.Two example applications including an open pit mine in weak rock and clay shale slope with daylighting bedding planes are presented.The results of limit equilibrium analysis and shear strength reduction method with perfectly-plastic models were in close agreement.Using perfectly-plastic models with peak strength properties led to overly optimistic results while adopting residual strength properties gave excessively conservative outcomes.The shear strength reduction method with a strain-softening model gave realistic factors of safety while accounting for the process of strength degradation.

An Evaluation of the Effects of Human Factors on Pilotage Operations Safety

In recent years,marine pilotage accidents occurring on a worldwide basis as a result of human error have not been ceased to transpire,despite advances in technology and a significant set of international conventions,regulations,and recommendations to reduce them.This paper aims to investigate the effect of human factors on the safety of maritime pilotage operations.The human factors that affect the operators who are performing ships’berthing operations have also been examined in detail.In this study,in order to determine the causes of human-related errors occurred in maritime pilotage accidents,a comprehensive literature review is carried out,and a considerable number of real past case examples and an analysis of the maritime accident investigation reports regarding pilotage operations events that occurred between 1995 and 2015 have been reviewed.To validate the identified humanrelated risk factors(HCFs)and explore other contributory factors,survey questionnaires and semi-structured interviews with domain experts have been conducted.A structural hierarchy diagram for the identified risk factors(HCFs)has been developed and validated through experienced experts belonging to the maritime sector.A questionnaire for pair-wise comparison is carried out and analysed using the analytic hierarchy process(AHP)approach to evaluate the weight and rank the importance of the identified human causal factors.The findings of this study will benefit the maritime industry,by identifying a new database on causal factors that are contributing to the occurrence of maritime pilotage disasters.The database can be used as a stand-alone reference or help implement effective risk reduction strategies to reduce the human error,that might occur during pilotage operations.

Factors associated with the incidence of patient falls in hospitals:A scoping review

When a patient falls within a hospital setting,there is a significant increase in the risk of severe injury or health complications.Recognizing factors associated with such falls is crucial to mitigate their impact on patient safety.This review seeks to analyze the factors contributing to patient falls in hospitals.The main goal is to enhance our understanding of the reasons behind these falls,enabling hospitals to devise more effective prevention strategies.This study reviewed literature published from 2013 to 2022,using the Arksey and O’Malley methodology for a scoping review.The research literature was searched from seven databases,namely,PubMed,ScienceDirect,Wiley Library,Garuda,Global Index Medicus,Emerald Insight,and Google Scholar.The inclusion criteria comprised both qualitative and quantitative primary and secondary data studies centered on hospitalized patients.Out of the 893 studies analyzed,23 met the criteria and were included in this review.Although there is not an abundance of relevant literature,this review identified several factors associated with falls in hospitals.These encompass environmental,patient,staff,and medical factors.This study offers valuable insights for hospitals and medical personnel aiming to enhance fall prevention practices.Effective prevention efforts should prioritize early identification of patient risk factors,enhancement of the care environment,thorough training for care staff,and vigilant supervision of high-risk patients.By comprehending the factors that contribute to patient falls,hospitals can bolster patient safety and mitigate the adverse effects of falls within the health-care setting.

Enhancing Fire Safety in Commercial Vehicles: Assessing the Efficacy and Advantages of Exploding Fire Extinguishing Balls

Fire incidents in commercial vehicles pose significant risks to passengers, drivers, and cargo. Traditional fire extinguishing systems, while effective, may have limitations in terms of response time, coverage, and human intervention [1]. This study investigates the efficacy of a novel fire suppression technology—the Exploding Fire Extinguishing Ball (EFEB) —as an alternative and complementary fire safety solution for commercial vehicles. The research employs a multidisciplinary approach, encompassing engineering, materials science, fire safety, and human factors analysis. A systematic literature review establishes a comprehensive understanding of existing fire suppression technologies, including EFEBs. Subsequently, this study analyzes the unique features of EFEBs, such as automatic activation, as well as manual activation upon exposure to fire, and their potential to provide rapid, localized, and autonomous fire suppression. The study presents original experimental investigations to assess the performance and effectiveness of EFEBs in various fire scenarios representative of commercial vehicles. Experiments include controlled fires in confined spaces and dynamic simulations to emulate real-world fire incidents. Data on activation times, extinguishing capability, and coverage area are collected and analyzed to compare the efficacy of EFEBs with traditional fire extinguishing methods. Furthermore, this research shows the practical aspects of implementing EFEBs in commercial vehicles. A feasibility study examines the integration challenges, cost-benefit analysis, and potential regulatory implications. The study also addresses the impact of EFEBs on vehicle weight, stability, and overall safety. Human factors and user acceptance are crucial elements in adopting new safety technologies. Therefore, this research utilizes an experimental design to assess the performance and effectiveness of EFEBs in various fire scenarios representative of commercial vehicles. This dissertation presents original controlled experiments to emulate real-world fire incidents, including controlled fires in confined spaces and dynamic simulations. The experimental approach ensures rigorous evaluation and objective insights into EFEBs’ potential as an autonomous fire suppression system for commercial vehicles. This includes the perspectives of drivers, passengers, fleet operators, insurance agencies, and regulatory bodies. Factors influencing trust, perceived safety, and willingness to adopt EFEBs are analyzed to provide insights into the successful integration of this technology. The findings of this research will contribute to the knowledge of fire safety technology and expand the understanding of the applicability of EFEBs in commercial vehicles.

Assessment of Axial Power Peaking Factors in GHARR-1 LEU Core: A Decadal Simulation Analysis

This study aims to thoroughly investigate the axial power peaking factors (PPF) within the low-enriched uranium (LEU) core of the Ghana Research Reactor-1 (GHARR-1). This study uses advanced simulation tools, like the MCNPX code for analysing neutron behavior and the PARET/ANL code for understanding power variations, to get a clearer picture of the reactor’s performance. The analysis covers the initial six years of GHARR-1’s operation and includes projections for its whole 60-year lifespan. We closely observed the patterns of both the highest and average PPFs at 21 axial nodes, with measurements taken every ten years. The findings of this study reveal important patterns in power distribution within the core, which are essential for improving the safety regulations and fuel management techniques of the reactor. We provide a meticulous approach, extensive data, and an analysis of the findings, highlighting the significance of continuous monitoring and analysis for proactive management of nuclear reactors. The findings of this study not only enhance our comprehension of nuclear reactor safety but also carry significant ramifications for sustainable energy progress in Ghana and the wider global context. Nuclear engineering is essential in tackling global concerns, such as the demand for clean and dependable energy sources. Research on optimising nuclear reactors, particularly in terms of safety and efficiency, is crucial for the ongoing advancement and acceptance of nuclear energy.

Residual fatigue strength of 48MnV crankshaft based on safety factor

Residual fatigue strength of 48MnV crankshaft was studied and analyzed based on safety factor. Three different status crankshafts were used to the hop-up tests, which maintain new after 500h hop-up tests and after 1000h hop-up tests. Then, crankshafts were cut into unit cranks. The unit cranks were used to do endurance bending tests to get the residual fatigue strength. Finally, the results were analyzed based on safety factor. The results show that safety factor of crankshaft descends a little with the increase of the running time, and the residual safety factor is still much bigger than the endurable safety factor. Furthermore, after the crankshaft accomplishes a full life cycle, the residual fatigue strength of the crankshaft is enough to remanufacture and fulfill the next life cycle.

Toroidicity Dependence of Tokamak Edge Safety Factor and Shear

Using a simple analytical model equilibrium, the dependence of tokamak edge safety factor qedge which can be understood as qa for a limiter device or 595 for a divertor device, and the shear value are calculated and compared with the ITRE-recommended formula. This dependence relation is useful in designing the medium and small aspect ratio tokamaks and reactors.

Hysteresis of Dam Slope Safety Factor under Water Level Fluctuations Based on the LEM Coupled with FEM Method

Water level variations have caused numerous dam slope collapse disasters around the world,illustrating the large influence of water level fluctuations on dam slopes.The required indoor tests were conducted and a numerical model of an actual earth-filled dam was constructed to investigate the influences of the water level fluctuation rate and the hysteresis of the soil-water characteristic curve(SWCC)on the stability of the upstream dam slope.The results revealed that the free surface in the dam body for the desorption SWCC during water level fluctuations was higher than that for the adsorption SWCC,which would be more evident at higher water levels.The safety factor of the upstream dam slope initially decreased and then increased for the most dangerous water level as the water level rose and fell.The water level fluctuation rate mainly influenced the initial section of the safety factor variation curve,while the SWCC hysteresis mainly affected the minimum safety factor of the water level fluctuations.The desorption SWCC is suggested for engineering design.Furthermore,a quick prediction method is proposed to estimate the safety factor of upstream dam slopes with identical structures.

Relationship between critical seismic acceleration coefficient and static factor of safety of 3D slopes

Many analytical methods have been adopted to estimate the slope stability by providing various stability numbers,e.g.static safety of factor(static FoS)or the critical seismic acceleration coefficient,while little attention has been given to the relationship between the slope stability numbers and the critical seismic acceleration coefficient.This study aims to investigate the relationship between the static FoS and the critical seismic acceleration coefficient of soil slopes in the framework of the upper-bound limit analysis.Based on the 3D rotational failure mechanism,the critical seismic acceleration coefficient using the pseudo-static method and the static FoS using the strength reduction technique are first determined.Then,the relationship between the static FoS and the critical seismic acceleration coefficient is presented under considering the slope angleβ,the frictional angleφ,and the dimensionless coefficients B/H and c/γH.Finally,a fitting formula between the static FoS and the critical seismic acceleration coefficient is proposed and validated by analytical and numerical results.

Efficacy and safety of anti-vascular endothelial growth factor agents on corneal neovascularization: A meta-analysis

BACKGROUND Corneal neovascularization(CoNV)is the second major cause of blindness.Vascular endothelial growth factor(VEGF)inhibitors,e.g.,bevacizumab,have been used to prevent CoNV.AIM We conducted an updated systematic review and meta-analysis of clinical trials to examine the efficacy and safety of anti-VEGF in CoNV.METHODS A literature search was conducted using three electronic databases.Mean difference(MD),standard mean difference(SMD),and relative risk(RR)are used to estimate the effect size.RESULTS Nine randomized controlled and three non-randomized trials were obtained.The pooled results demonstrated a significant reduction of CoNV area/Length(SMD=-1.17,95%CI:-1.58 to-0.75),best corrected visual acuity(MD=-0.54,95%CI:-0.91 to-0.17),and graft rejection(RR=0.44,95%CI:0.24 to 0.8)and failure(RR=0.39,95%CI:0.19 to 0.78)rates in the anti-VEGF group than the placebo group.A non-significant reduction of the epithelial defect was also observed in the bevacizumab group compared with the placebo(RR=0.56,95%CI:0.30 to 1.06).Compared with a placebo,the unsynthesizable trials also support that bevacizumab improves visual acuity,CoNV,graft rejection,and failure rates.Trials reporting other comparisons revealed the superiority of combined remedy with bevacizumab compared to other treatments in reducing CoNV.CONCLUSION Anti-VEGF agents,mainly bevacizumab,are an effective and safe treatment for CoNV of all causes and prevent corneal graft rejection and failure in corneal transplantation.

Limit equilibrium method(LEM) of slope stability and calculation of comprehensive factor of safety with double strength-reduction technique

When the slope is in critical limit equilibrium(LE) state, the strength parameters have different contribution to each other on maintaining slope stability. That is to say that the strength parameters are not simultaneously reduced. Hence, the LE stress method is established to analyze the slope stability by employing the double strengthreduction(DSR) technique in this work. For calculation model of slope stability under the DSR technique, the general nonlinear Mohr–Coulomb(M–C) criterion is used to describe the shear failure of slope. Meanwhile, the average and polar diameter methods via the DSR technique are both adopted to calculate the comprehensive factor of safety(FOS) of slope. To extend the application of the polar diameter method, the original method is improved in the proposed method. After comparison and analysis on some slope examples, the proposed method's feasibility is verified. Thereafter, the stability charts of slope suitable for engineering application are drawn. Moreover, the studies show that:(1) the average method yields similar results as that of the polardiameter method;(2) compared with the traditional uniform strength-reduction(USR) technique, the slope stability obtained using the DSR techniquetends to be more unsafe; and(3) for a slope in the critical LE state, the strength parameter φ, i.e., internal friction angle, has greater contribution on the slope stability than the strength parameters c, i.e., cohesion.

Development of Safety Factors for the UT Data Analysis Method in Plant Piping

There are several thousand piping components in a nuclear power plant. These components are affected by degradation mechanisms such as FAC (Flow-Accelerated Corrosion), cavitation, flashing, and LDI (Liquid Droplet Impingement). Therefore, nuclear power plants implement inspection programs to detect and control damages caused by such mechanisms. UT (Ultrasonic Test), one of the non-destructive tests, is the most commonly used method for inspecting the integrity of piping components. According to the management plan, several hundred components, being composed of as many as 100 to 300 inspection data points, are inspected during every RFO (Re-Fueling Outage). To acquire UT data of components, a large amount of expense is incurred. It is, however, difficult to find a proper method capable of verifying the reliability of UT data prior to the wear rate evaluation. This study describes the review of UT evaluation process and the influence of UT measurement error. It is explored that SAM (Square Average Method), which was suggested as a method for reliability analysis in the previous study, is found to be suitable for the determination whether the measured thickness is acceptable or not. And, safety factors are proposed herein through the statistical analysis taking into account the components’ type.

Method of Calculating the Safety Factor Profile on the HT-7 Tokamak

A method of calculating the safety profile on the HT-7 tokamak has been described in this paper. It is derived from Maxwell's equations, among which we-mainly use .two of them: one is the magnetic field diffusion equation, and the other is Ampere's Law. This method can be also used to evaluate the safety factor on other devices with a circular cross sections. It is helpful to the study of the plasma MHD behavior on the HT-7 tokamak.