105 research outputs found

    Factors and optimizations of healthcare workers' perception in alternative care facilities

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    BackgroundDiverse measures have been carried out worldwide to establish Alternative Care Facilities (ACFs) for different ends, such as receiving, curing or isolating patients, aiming to cope with tremendous shock in the urban medical system during the early passage of the COVID-19 epidemic. Healthcare workers always felt anxious and stressed during multiple major public health emergencies in medical facilities. Some active measures to improve healthcare workers' perceptions, such as temporary training, workflow improvement, and supplementary facilities, were proved insufficient in several past public health emergencies. Therefore, this study aims to analyze the contributing factors of the healthcare workers' perceptions of the ACFs in this pandemic, which can help find an innovative path to ensure their health, well-being and work efficiency.MethodThis paper conducted semi-structured in-depth interviews with the world's first batch of healthcare workers who have worked in ACFs through a qualitative study based on Grounded Theory. The healthcare workers interviewed from Heilongjiang, Shandong, Fujian, and Hubei provinces, have worked in one of the four different ACFs built in Wuhan. The results are obtained through the three-level codes and analyses of the interview recordings.ResultsThe factors affecting the perception of healthcare workers in ACFs during the epidemic situation can be summarized into five major categories: individual characteristics, organization management, facilities and equipment, space design, and internal environment. The five major categories affecting the composition of perception can be further divided into endogenous and exogenous factors, which jointly affect the perception of healthcare workers in ACFs. Among them, individual characteristics belong to endogenous factors, which are the primary conditions, while other categories belong to exogenous factors, which are the decisive conditions.ConclusionThis paper clarifies factors affecting the perception of healthcare workers in ACFs and analyzes the mechanism of each factor. It is posited that the passive strategies are a promising solution to protect healthcare workers' health, improve their work efficiency, and help reduce the operation stress of ACFs. We should train multidisciplinary professionals for future healthcare and enhance collaborations between healthcare workers and engineers. To sum up, this paper broadens new horizons for future research on the optimization of ACFs and finds new paths for alleviating healthcare workers' adverse perceptions of ACFs

    Task-Agnostic Learning to Accomplish New Tasks

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    Reinforcement Learning (RL) and Imitation Learning (IL) have made great progress in robotic control in recent years. However, these methods show obvious deterioration for new tasks that need to be completed through new combinations of actions. RL methods heavily rely on reward functions that cannot generalize well for new tasks, while IL methods are limited by expert demonstrations which do not cover new tasks. In contrast, humans can easily complete these tasks with the fragmented knowledge learned from task-agnostic experience. Inspired by this observation, this paper proposes a task-agnostic learning method (TAL for short) that can learn fragmented knowledge from task-agnostic data to accomplish new tasks. TAL consists of four stages. First, the task-agnostic exploration is performed to collect data from interactions with the environment. The collected data is organized via a knowledge graph. Compared with the previous sequential structure, the knowledge graph representation is more compact and fits better for environment exploration. Second, an action feature extractor is proposed and trained using the collected knowledge graph data for task-agnostic fragmented knowledge learning. Third, a candidate action generator is designed, which applies the action feature extractor on a new task to generate multiple candidate action sets. Finally, an action proposal is designed to produce the probabilities for actions in a new task according to the environmental information. The probabilities are then used to select actions to be executed from multiple candidate action sets to form the plan. Experiments on a virtual indoor scene show that the proposed method outperforms the state-of-the-art offline RL method: CQL by 35.28% and the IL method: BC by 22.22%.Comment: 11 pages, 11 figures, Under Revie

    Computational prediction of ideal strength for a material

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    The ideal strength is crucial for predicting material behavior under extreme conditions, which can provide insights into material limits, guide design and engineer for enhanced performance and durability. In this work, we present a method within an allows for the estimation of tensile, shear, and indentation strengths in any crystallographic direction or plane. We have examined the strain-stress relationships of several well-known structures and compared our findings with previous work, demonstrating the effectiveness of our approach. Moreover, we performed extensive investigations into the indentation strength of hexagonal WC, \b{eta}-SiC, and MgAl2O4l_2O_4. The current study uncovers the modes of structural deformation and the underlying atomistic mechanisms. The insights gained from this study have significant implications for the further exploration and design of superhard materials.Comment: 15 pages,7 figure

    Effect of Inclination Angle on the Response of Double-row Retaining Piles: Experimental and Numerical Investigation

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    The excavation depth of foundation pits has been increasing along with the continuous development of underground space and high-rise buildings. As a result, traditional double-row vertical piles cannot meet the ground settlement and deflection requirements. This study proposed a double-row pile optimization method to extend the suitability of double-row retaining piles to greater excavation depth. The optimization model was established by adjusting the inclination angle of the front and rear piles. Physical scale model tests were performed to analyze the effect of the inclination angle on the pile head displacements and bending moments during excavations and step loadings using three schemes, namely, traditional double-row piles with vertical piles, double-row contiguous retaining piles with batter pile in the front row, and double-row contiguous retaining piles with batter pile in both rows. Numerical simulations were also conducted to verify the effectiveness of the inclination angle adjustment in optimizing the double-row piles. Results indicate that the increase in the displacement and bending moment of the double-row contiguous retaining batter piles is not evident during excavation and step loading when compared with those of the double-row vertical piles and the double-row contiguous retaining piles with batter pile in the front row. Thus, double-row contiguous retaining batter piles can be used in deep foundation pits. The tilt angle is also excessively small to reduce the lateral displacement of the foundation pit, and the optimal tilt angle is 8° – 16°. Although the embedment depth can influence the deformation of the double-row contiguous retaining batter piles significantly, a critical embedment depth may be reached. The findings of this study can provide references for the optimization of double-row piles in foundation pits

    Assessment Model of Ecoenvironmental Vulnerability Based on Improved Entropy Weight Method

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    Assessment of ecoenvironmental vulnerability plays an important role in the guidance of regional planning, the construction and protection of ecological environment, which requires comprehensive consideration on regional resources, environment, ecology, society and other factors. Based on the driving mechanism and evolution characteristics of ecoenvironmental vulnerability in cold and arid regions of China, a novel evaluation index system on ecoenvironmental vulnerability is proposed in this paper. For the disadvantages of conventional entropy weight method, an improved entropy weight assessment model on ecoenvironmental vulnerability is developed and applied to evaluate the ecoenvironmental vulnerability in western Jilin Province of China. The assessing results indicate that the model is suitable for ecoenvironmental vulnerability assessment, and it shows more reasonable evaluation criterion, more distinct insights and satisfactory results combined with the practical conditions. The model can provide a new method for regional ecoenvironmental vulnerability evaluation

    三次元有限要素法を用いた臼歯陶材焼付鋳造冠におけるメタルコーピング形態の力学的検討

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    Objectives To find the ideal form of coping for metal molar ceramic crowns, we evaluated their stress distributions under various loading conditions using three-dimensional finite element analysis. Materials and methods A three-dimensional finite element model representing a lower first molar was constructed. The model was varied to include one of three types of coping, the standard, butterfly, and flat types. A load of 600N, simulating the maximum bite force, was applied vertically to the crowns at the central occlusal surface and mesio-oc-clusal marginal areas. Loads of 225N, simulating masticatory force, were applied at a 45° angle to the tooth axis. Results In three of the simulation load tests, the maximum stresses were concentrated around the loading points on the porcelain and coping. The minimum tensile stress value was placed on the butterfly coping crown in the test simulating maximum bite force, when the load was applied to the mesio-occlusal marginal areas. Conclusion The butterfly coping design optimizes the stress distribution within copings and porcelain and enhances the structural strength of porcelain in metal ceramic crowns

    臼歯陶材焼付鋳造冠におけるメタルフレーム形態の力学的検討(英文)

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    Objectives: The purpose of this study was to find an ideal shape of the metal frame (coping) in the porcelain fused to metal (PFM) crown. The stress distribution was assessed by the load-to-fracture values and a three-dimensional finite element analysis. Methods: Three kinds of coping designs were tested; Design I: Conventional type as control (traditional frame). Design II: 1.0 mm lower than occlusal surface of coping (butterfly frame). Design III: Straight type (flat frame). The load-to-fracture value consisted of three groups (Design I, II and III) of five samples each. The loading location is selected at the area where mesial and distal of the metal frame will coincide with the projection of the occlussal surface. All samples were loaded to fracture at the rate of 0.1 mm/min using a universal-testing machine. The stress distribution was assessed in a three-dimensional finite element model, which consisted of the abutment tooth, cement, metal coping and porcelain. The loading position is the projection point ofbuccal-lingual transitional part of the frame mesial and distal proximal surface on the occlusal surface towards the median, in which the load is in constant value. Loading direction is vertically downward along tooth axis with a load of 2000 N. Results: The mean load-to-fracture value for each group is as follows: Group A (Design I)=1823.0 N±132.7 (S.D.), Group B (Design II)=1940.4 N±147.4 (S.D.), Group C (Design III)=2333.9 N±180.9 (S.D.). The results of the three-dimensional finite element analysis showed that the maximum tensile stress of 84.5 MPa occurred in Design I. The maximum tensile stress in design II and III were 53.8 MPa and 53.3 MPa, respectively, which were the lower than Design I. Conclusions: The results indicated that the butterfly and flat frame designs will increase metal support on proximal porcelain, thus effectively change the stress distribution within the coping and porcelain, optimizing stress distribution in PFM crown under perpendicular load, and enhance structural strength of porcelain of PFM crown
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