Bearing-shaft systems are essential components in various automated manufacturing processes, primarily designed for the efficient rotation of a main shaft by a motor. Accurate fault detection is critical for operating manufacturing processes, yet challenges remain in sensor selection and optimization regarding types, locations, and positioning. Sound signals present a viable solution for fault detection, as microphones can capture mechanical sounds from remote locations and have been traditionally employed for monitoring machine health. However, recordings in real industrial environments always contain non-negligible ambient noise, which hampers effective fault detection. Utilizing a high-performance microphone for noise cancellation can be cost-prohibitive and impractical in actual manufacturing sites, therefore to address these challenges, we proposed a convolution neural network-based methodology for fault detection that analyzes the mechanical sounds generated from the bearing-shaft system in the form of Log-mel spectrograms. To mitigate the impact of environmental noise in recordings made with commercial microphones, we also developed a denoising autoencoder that operates without requiring any expert knowledge of the system. The proposed DAE-CNN model demonstrates high performance in fault detection regardless of whether environmental noise is included(98.1%) or not(100%). It indicates that the proposed methodology effectively preserves significant signal features while overcoming the negative influence of ambient noise present in the collected datasets in both fault detection and fault type classification.
In this paper, we investigate asteroseismic scaling-relations of evolved stars in star clusters observed by Kepler/K2, aiming to address the issue of whether observed stellar oscillations are influenced by environmental factors, as there are interesting phenomena relating to the stellar pulsations observed in star clusters. Specifically, we compare statistical properties of distributions including Δν, νmax, HGauss, δνenv, and δν02 derived from red giant branch (RGB) and red clump (RC) stars in two pairs of star clusters: NGC 2682 - NGC 6819 and NGC 1817 - NGC 6811. We have found that the slopes of relations between νmax and Δν and between HGauss and νmax associated with RC stars in the more compact star clusters, NGC 2682 and NGC 1817, are in common less steep compared with those for NGC 6819 and NGC 6811. It is also found that the slopes of the relation between δνenv and νmax from RC stars in the more compact star clusters are in common steeper compared with those for the others. For the relation between δν02 and Δν obtained from RGB stars, the slope resulting from NGC 2682 and NGC 6819 is indistinguishable. The Kolmogorov–Smirnov tests conducted on RC stars in the pairs of NGC 2682 and NGC 6819, as well as NGC 1817 and NGC 6811, indicate that all the seismic quantities considered in this paper are drawn from different distributions. We conclude, therefore, that the properties of star clusters should be considered when asteroseismic data obtained from stars within star clusters are interpreted.
Much effort has been carried out to calibrate and revise asteroseismic relations, given their importance of relations in asteroseismology in determining fundamental parameters of stars. In this study, we statistically explore asteroseismic relations with partial correlation coefficients to determine the most fundamental parameters, separately analyzing asteroseismic data based on the evolutionary status of stars from main sequence up to core helium-burning red-clump stars. We have found that regardless of the evolutionary status of the sampled stars the surface gravity and density of stars strongly influence the observed correlations. More importantly, it is found that indirect correlations derived considering the influence of confounding parameters are subject to the evolutionary status. For example, the observed correlation of the large frequency separation Δν with the central frequency νmax is influenced by the stellar mass, radius, and luminosity only for main sequence stars. The observed correlation of the width of the Gaussian envelope δνenv with νmax is influenced by the stellar mass, effective temperature, radius, and luminosity for main-sequence and subgiant stars. The observed relation between Δν and the small frequency separation δν02 is influenced by the stellar mass, radius, and luminosity for main-sequence and subgiant stars. In contrast, effective temperature, metallicity, and age do not seem to significantly affect the observed correlations. Finally, we conclude by discussing implication of our findings.
Zooplankton biomass is essential for understanding the quantitative structure of lake food webs and for the functional assessment of biotic interactions. In this study, we aimed to propose a biomass (dry weight) estimation method using the body length of cyclopoid copepods. These copepods play an important role as omnivores in lake zooplankton communities and contribute significantly to biomass. We validated several previously proposed estimation equations against direct measurements and compared the suitability of prosomal length versus total length of copepods to suggest a more appropriate estimation equation. After comparing the regression analysis results of various candidate equations with the actual values measured on a microbalance-using the coefficient of variation, mean absolute error, and coefficient of determination-it was determined that the Total Length-DW exponential regression equation [W=0.7775×e2.0183L; W (μg), L (mm)] could be used to calculate biomass with higher accuracy. However, considering practical issues such as the morphological similarity between species and genera of copepods and the limitations of classifying copepodid stages, we derived a general regression equation for the pooled copepod community rather than a species-specific regression equation.
Modification of the surface of raw activated carbon using chemical solvents can significantly improve the adsorption performance of activated carbon. Triethylenetetramine is one of the most important chemical solvents used to modify raw activated carbon for formaldehyde removal indoor. We conducted the liquid impregnation experiments at different initial concentrations, temperatures, adsorbent dosage and time ranges to fully investigate the adsorption of triethylenetetramine on the surface of raw activated carbon for modification. We found that the Langmuir isotherm model and pseudo-first-order kinetic model fit quite well with the experimental data and the R2 are 0.9883 and 0.9954, respectively. The theoretical maximum adsorption capacity is 166.67 mg/g. The change in Gibbs free energy (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were also calculated to study the direction and driving force of the liquid adsorption process. In order to understand the adsorption process at the molecular level, a new activated carbon model based on the actual physical and chemical properties of activated carbon was carefully established in the Materials Studio to simulate the liquid-phase adsorption. The pore structure, elemental composition, functional group content, density, pore volume, and porosity of the activated carbon model converge close to the actual activated carbon and the adsorption isotherms obtained from the simulation agree well with the experimental results. The results show that the adsorption of triethylenetetramine on activated carbon is a spontaneous, endothermic and monolayer physical adsorption process.
Green product experience has become an important marketing strategy for corporations to tap potential green consumers. Based on the theory of planned behavior, this article explores the influence of attitude, subjective norm, and perceived behavioral control on consumers’ green purchasing intentions from the perspective of green product experience with consumers in China, Japan, and Korea as the research objects. Our findings suggest that green product experience of consumers in the three countries can directly affect consumers' green purchasing intentions. Green product experience has an indirect influence on consumers’ green purchasing intention through the mediating effect of attitude, subjective norm and perceived behavioral control. The multiple group comparison shows the external validity of TPB through an examination of green purchasing behavior in different cultural settings, which will help enterprises implement effective experience marketing strategies.
To understand antioxidant enzyme response of two contrasting Arundinella hirta ecotypes to drought stress, drought-tolerant Youngduk and drought-sensitive Jinju-1, were comparatively analyzed changes in the enzymatic activities of peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR). Two ecotypes, drought-tolerant Youngduk and drought-sensitive Jinju-1 were subjected to drought stress by withholding water for 12 days. ROS accumulation level and electrolytic leakage were significantly increased in both A. hirta ecotypes by drought stress treatment but less in Youngduk than Jinju-1. The RWC significantly decreased in both the drought stress-treated ecotypes as compared to control, but less in Youngduk than Jinju-1. Soluble sugar and protein content were increased more in drought stress-treated Youngduk as compared to Jinju-1. The activities of antioxidant enzymes such as SOD, CAT, POD, APX, and GR increased significantly in both the drought stress-treated ecotypes Youngduk and Jinju-1 as compared to control. The increase in antioxidant enzyme activity level was more prominent in drought stress-treated Youngduk as compared to Jinju-1. Taken together, these results suggest that Youngduk was more tolerant to drought stress than Jinju-1, and seem to indicate that tolerance of A. hirta to drought stress is associated with increased activity of antioxidant enzymes.
We explore the latitudinal distribution of sunspots and pursue to establish a correlation between the statistical parameters of the latitudinal distribution of sunspots and characteristics of solar activity. For this purpose, we have statistically analyzed the daily sunspot areas and latitudes observed from May in 1874 to September in 2016. As results, we confirm that the maximum of the monthly averaged International Sunspot Number (ISN) strongly correlates with the mean number of sunspots per day, while the maximum ISN strongly anti-correlates with the number of spotless days. We find that both the maximum ISN and the mean number of sunspots per day strongly correlate with the the average latitude, the standard deviation, the skewness of the the latitudinal distribution of sunspots, while they appears to marginally correlate with the kurtosis. It is also found that the northern and southern hemispheres seem to show a correlated behavior in a different way when sunspots appearing in the northern and southern hemispheres are examined separately.
When we think about an idea of United Nations Tolerance Program UNTP, it is important for us to share memory with world citizens that we had 2314 veterans from 11 countries in the Busan U.N. Forces Cemetery since January of 1951. Recently, we had 13 veterans, who got buried coming from 4 Americans, 3 Hollanders, 2 Frenchmen, 2 Germans, 2 Englishmen, 1 Canadian and 1 headband after they died in their countries. (Joongang daily newspaper June 19, 2022). "I believe that creating a fifth office of the UNTP in Republic of Korea (Seoul, Busan, Kyunggi or Jeju Island), as a twin organization of the UNEP in Nairobi, Kenya, would provide a geopolitical balance to the international organization and a useful base for peace island studies in the conflict laden region of East Asia. Establishing this office in S. Korea(Seoul, Busan, Kyunggi or Jeju Island), with its unique geographical location as a hub for peace talks and environmental negotiations between Russia, North Korea, Japan, China, and Taiwan, would contribute to peace and development in the region." (Yates. 2022).
We assume that, even though Jeju Island ‘Peace’ Cherry Trees (1913), happened at different time and places, it connects each other as (1919) and Busan UN Forces Cemetery (1951) as an important connected diplomatic event of Provisional Government and Republic of Korea positively. Especially, it will bring a significant positive impact to Asia Community if we organize 2023 Korean Week Event: The First Korea Congress (1919) and Busan UN Forces Cemetery (1951) and suggest the invitation issues of UN Asia Headquarters to the Republic of Korea (2023) into Busan metropolitan city(Seoul, Kyunggi, Jeju Special Self-Governing Province) of Republic of Korea. We also assume Korean’s tolerance philosophy will Koreans to unite each other together if they will succeed to share spirit of tolerance from Busan UN Forces Cemetery. We have 2314 graves from 11 countries at the graveyard for UN Forces in Busan, which was built as the UN Headquarters Cemetery in January of 1951 and used as memorial space for participation in the Korean War, who had involved the War beyond their sacrifices. Recently we had 13 veterans, who got buried coming from 4 Americans, thre Hollanders, 2 Frenchmen, 2 Germans, 2 Englishmen, 1 Canadian and 1 headband after they died in their countries. (Joongang daily newspaper June 19, 2022). In the end they become Asian spirit of Toleran명 at the Busan UN Forces Cemetery beyond borders.
This study aims to restore the dignity of the elderly based on “filial piety” and community values in preparation for the 'silver tsunami' in Jeju by studying the case of Whitney Center in the United States, PASSi, Jeju's Isidol Nursing Home, and the haenyeo society. The main goal was to develop the Asian Jeong Nang model which was named by professor Koh Chang Hoon, Chair of Island Research Institute at Jeju National university. Jeong Nang(정낭) is the gateway with 3 wooden bars to the traditional residential space of Jeju where several generations live together. Dr. Hesung Chun Koh, Chair of East Rock Institute gave me motivation and support for the study of the elderly welfare model at the Jeju National University Island Research Institute. As the head of this study, I was dispatched from the Jeju National University Island Research Institute to the East Rock Institute (ERI). Dr. Hesung Chun Koh, M.D. Ann Datunashivili who is a practice professor at Medical School of Yale and in charge of Medical Center of Whitney Center. and Mike RambaRose who is Chief Executive Officer of Whitney Center, supported my research. In addition ImJa Choi, CEO of PASSi, also allowed two research students, Lee Seung Yong and Ko Yu Seok, from Jeju National University, to help my research related to psycho-social approach for the elderly at PASSi. This study was intended to develop a model for senior citizens in Korea through Hesung Chun Koh's ERI CCAI Model, Whitney Center's residential apartment model for retired seniors, and PASSi's community care model for the multi-cultural community.