COMPRESSIVE CREEP AND RECOVERY BEHAVIORS OF SEAT CUSHIONS IN UPHOLSTERED FURNITURE

This study investigated effects of compressive load magnitude and cover and core materials on the force-deformation-time behavior of seat cushions commonly used in upholstered furniture. Results indicated that the Burger and Kelvin models could be used to describe the creep and recovery behavior of a furniture seat cushioning system composed of foam, spring, and cover materials, respectively. Statistical analyses of experimental data indicated that the magnitude of creep loads had significant effects on the viscoelastic constants in mathematical expressions derived from the Burger model for describing the force-deformation-time behavior of the cushions evaluated. Foam cushions with coil springs had significantly greater viscoelastic constants than those without. Changing cushion cover material from leather to fabric had no significant effect on the elastic constant of tested cushion materials, but increased theviscous constant and delayed elastic-deformation-related damping constants

EFFECT OF THE Si POWDER ADDITIONS ON THE PROPERTIES OF SiC COMPOSITES

By means of transient plastic phase process, the SiC silicon carbide kiln furniture materials were produced through adding Si powder to SiC materials. At the condition of the same additions of SiO2 powder, the effect of the Si powder additions on properties of silicon carbide materials after sintered at 1450°C for 3 h in air atmosphere was studied by means of SEM and other analysis methods. The results showed that silicon powder contributes to both sintering by liquid state and plastic phase combination to improve the strength of samples. When the Si powder additions is lower than 3.5 %, the density and strength of samples increase and porosity decrease with increasing Si powder additions. However when the Si powder additions is higher than 3.5 %, the density and strength of samples decrease and porosity increase with increasing Si powder additions. With increasing of Si additions, the residual strength of sample after thermal shocked increased and linear change rate decreased, and get to boundary value when Si additions is 4.5 %. The results also indicated that at the same sintering temperature, the sample with 3.5 % silicon powder has maximum strength

Parameter Estimation of Induction Machine at Standstill Using Two-Stage Recursive Least Squares Method

This paper presents a two-stage recursive least squares (TSRLS) algorithm for the electric parameter estimation of the induction machine (IM) at standstill. The basic idea of this novel algorithm is to decouple an identifying system into two subsystems by using decomposition technique and identify the parameters of each subsystem, respectively. The TSRLS is an effective implementation of the recursive least squares (RLS). Compared with the conventional (RLS) algorithm, the TSRLS reduces the number of arithmetic operations. Experimental results verify the effectiveness of the proposed TSRLS algorithm for parameter estimation of IMs

Do financial asset holdings affect investor expectations under negative events? The shock of COVID-19 pandemic

Holding excessive financial assets will lead to corporate financialization, making investors underestimate its risks in front of extreme benefits and the “reservoir effect” in boom periods, especially in rapid-growing emerging economies. Few studies have explored the investors’ real perceptions and attitudes towards such risks when dealing with unexpected shocks. The 2019 novel coronavirus disease (COVID-19) provides new insights into these questions. Using event study method, this study examines how investors react to corporate financialization in the risk-release condition. First, we find that firms with more financial asset holdings experience significant lower market return during the COVID-19 pandemic. Second, we find that the pandemic-induced drop in stock returns is milder when firms hold more low-liquidity or safe financial assets, have higher solvency, are less exposed to COVID- 19 pandemic and have better information environment. These findings show that the investors’ attitude is widely negative towards corporate financialization when the negative shock comes and strong financial flexibility and good corporate governance can alleviate the risk. It implicates that the hidden risks of corporate financialization can be perceived by investors and responded by “voting with their feet” and the managers should be alert to it rather than just seeking financial benefits

Hyper Association Graph Matching with Uncertainty Quantification for Coronary Artery Semantic Labeling

Coronary artery disease (CAD) is one of the primary causes leading to death worldwide. Accurate extraction of individual arterial branches on invasive coronary angiograms (ICA) is important for stenosis detection and CAD diagnosis. However, deep learning-based models face challenges in generating semantic segmentation for coronary arteries due to the morphological similarity among different types of coronary arteries. To address this challenge, we propose an innovative approach using the hyper association graph-matching neural network with uncertainty quantification (HAGMN-UQ) for coronary artery semantic labeling on ICAs. The graph-matching procedure maps the arterial branches between two individual graphs, so that the unlabeled arterial segments are classified by the labeled segments, and the coronary artery semantic labeling is achieved. By incorporating the anatomical structural loss and uncertainty, our model achieved an accuracy of 0.9345 for coronary artery semantic labeling with a fast inference speed, leading to an effective and efficient prediction in real-time clinical decision-making scenarios.Comment: 8 pages, 2 figure

Effect of Coating Thickness on Sound Absorption Property of Four Wood Species Commonly Used for Piano Soundboards

Effects of polyurethane (PU) coating thicknesses (0.15, 0.30, 0.45, and 0.60 mm) on sound absorption coefficients of four wood species were investigated using the standing wave ratio method with an input sound vibration frequency range set between 125 and 4000 Hz. Wood species of four specific gravity (SG) levels were Korean spruce, European spruce, Sitka spruce, and Picea brachytyla. Experimental results indicated that PU coating can significantly increase sound absorption coefficients of higher SG species such as Sitka spruce and Picea brachytyla in all tested frequency levels, but this significant increase was not observed in lower SG species such as Korean and European spruces when tested in the frequency range from 800 to 2000 Hz. Effects of coating thickness on sound absorption coefficients of four evaluated species were found to interact with wood SG values and input sound vibration frequency ranges. Specifically, coating 0.30-mm-thick PU on Korean and European spruces tends to result in significantly lower sound absorption coefficients among the ones coated with four evaluated thicknesses when tested at the frequency less than 800 Hz, but PU coating thickness resulting in lower sound absorption coefficients on Sitka spruce and Picea brachytyla was 0.15 mm. Sitka spruce and Picea brachytyla coated with 0.30- and 0.6-mm-thick PU had lower sound absorption coefficients when tested at the frequency ranging from 1000 to 2000 Hz. When tested at the frequency greater than 2500 Hz, sound absorption coefficients of four coated species increased as coating thickness increased from 0.30 to 0.60 mm with an increment of 0.15 mm, but these four species coated with three thicker PU had significantly lower sound absorption coefficients than the ones coated with 0.15-mm-thick PU. The uncoated higher SG species tended to have lower sound absorption coefficients than uncoated lower SG ones when tested in the frequency ranging from 500 to 4000 Hz, but the differences were not found when tested under the frequency less than 400 Hz. Coating four species with different thicknesses of PU could alter their SG effects on their sound absorption coefficients