• The Journal of Information Systems
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• v.30 no.3
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• pp.47-64
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• 2021

Purpose This study measures the degree of improvement in statistical quality experienced by data users when the data of a more convenient measurement method is extended to the analysis target to improve the quality of fine dust statistics service, and the method of expressing analysis data is revised. Ultimately, the main purpose is to explore how it can affect the quality of life of citizens. Design/methodology/approach As it was an issue the emerged as the most important issue at the time, various parties (government, private company, academia, civic groups, etc.) conducted multifaced research on fine dust, but they all focused on measuring technology and demonstrating its effectiveness there was only. This researcher redesigned the study from the viewpoint of statistical data users by changing the research subject from the technology itself to user, different from the existing research cases. The questionnaire method and structural equation were used in the study, and fine dust statistics generated through the existing method and the expanded/revised method were provided and compared for a total of 200 people. Findings Based on the results of the study, I would like to suggest what each entity should ultimately focus on to resolve the fine dust issue in the future.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.63.3-63.3
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• 2019

Active asteroids are celestial bodies that distinctively have asteroid-like orbital elements but show comet-like activity. They exhibit the activities due to the sublimation of volatile ices, impacts with small objects or break-up by rapid rotations. As of 2019 February, 30 active asteroids are detected in the outer main belt (i.e., the semimajor axes a>2.5 au) while only 3 of them in the inner main belt (a<2.5 au), suggesting that sublimation of remaining icy volatiles can be one of the most fundamental mechanisms for the activities. A sudden activity of (6478) Gault was reported in early 2019. The asteroid was discovered in 1988 and has exhibited its inactive appearance until the end of last year. Soon after the report, we have conducted imaging observations using the Seoul National University Observatory 1.0-m telescope and the Korea Microlensing Telescope Network (KMTNet) to monitor the activity. The observed images showed a primary dust tail that consists of dust grains ejected early November in 2018. Later, another tail developed, indicating further dust ejection occurred around late December 2018. Our model simulation to reproduce the morphology of the dust cloud suggests that the slightly-curved primary dust tail results from a continuous dust ejection over weeks. The total mass of ejecta was estimated to XX kg (XX% of the asteroid mass). Such continuous dust ejection for the inner active asteroids was unexpected because ice might have already sublimated from subsurfaces of inner main belt. Based on our observational evidence, we will discuss how inner asteroids are activated and eject dust continuously.

• Journal of English Language & Literature
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• v.56 no.2
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• pp.383-408
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• 2010

This paper intends to suggest the positive, ecological vision of sustainability in Karen Hesse's Out of the Dust that Billie Jo Kelby recovers herself through her readjustment of interior consciousness and outer environment in her tragic situations caused by the Dust Bowl. In spite of her desires for happiness and affluence of home, she loses her mother and brother, and her musical talent as a pianist, and lies in self-abandonment. But she finally raises up herself with her courage and patience, reconciliating with the nature and ameliorating the community by taking care of the devastated landscapes. Hence it is appropriate to approach the loss-recovery process of nature and consciousness with ecological solutions, The Dust Bowl breaks down human mind and body, and eventually leads to the situations of despairs and death. Hesse proposes the primary solution that humans should reconstruct their interior consciousness and participate in recovering the nature because humans are inevitably linked with nature. In this novel, the nature takes a dynamic and active role as a catalyst, reconciling the self with other humans and settling with the conflicting situations in history and culture. This verse novel as an active, self-ordering, and corrective process gives the more intense ecological message. As Hesse defines the setting of Dirty Thirties as a channel of energy, she creates the utmost effects of ecological process that human and environment are part of a total situation, representing the transactional formulation, each conditioned by conditioning to the other. Therefore Billie Jo takes her part as an interpreter and actualizes herself, understanding the nature with metaphor and symbol. Eventually Billie Jo realizes that she should rebuild her environment not out of the dust but in the dust, accepting the reality of Dust Bowl.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.4
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• pp.393-401
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• 2013

Objectives: Endotoxins in dust generated in occupational settings is known to contribute to the occurrence of respiratory illness among workers. The relationship between the level of endotoxins in total dust or respirable particulates collected from swine farms and immunological markers related with respiratory allergy was evaluated among swine husbandry workers. Materials and Methods: Peripheral blood samples were collected from ten workers at ten swine farms at Gyeonggi province, Korea. Peripheral mononuclear cells were stimulated with phorbol 12-myristate 13-acetate and ionomycin for 48 hours. The levels of various cytokines produced at culture supernatants were determined using a commercially available ELISA kit. The concentration of particulate matter($PM_{10}$) in the indoor air of the swine farms was evaluated using a PVC membrane filter and mini volume air sampler, and endotoxin levels in the dust were measured by Limulus Amebocyte Lysate Kinetic QCL method. Results: Levels of endotoxins in the total dust were categorized into high(geometric mean: $109.35EU/m^3$) and low concentrations (geometric mean: $0.95EU/m^3$) for five swine farms. Interleukin-4 levels were higher in the high endotoxin group than in the low endotoxin group, while interferon-${\gamma}$ levels were lower in the high endotoxin group than in the low endotoxin group. The ratio (interferon-${\gamma}$ to interleukin-4), indicating immunologic skewedness against allergic reactivities, was lower in the high endotoxin group($1.15{\pm}0.60$) than the low endotoxin group($3.09{\pm}2.38$). In addition, the level of interleukin-13, another cytokine contributing to the occurrence of allergic responses, was significantly higher in the at the high endotoxin group($1.12{\pm}0.37ng/m{\ell}$) than in the low endotoxin group($0.37{\pm}0.04ng/m{\ell}$). Hematologic assessment showed significantly lower cellularity in the number of total leukocytes, neutrophils, and eosinophils in the high endotoxin group than in the low endotoxin group. Conclusions: Even though a sufficient number of swine workers and farms were not investigated, this study generlly suggests that the immunological function of swine farm workers exposed to high levels of endotoxin could be modulated toward allergic reactivities.

• Journal of Preventive Medicine and Public Health
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• v.23 no.3 s.31
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• pp.262-273
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• 1990

In order to assess the method which is more sensitive one to detect the early change of lung tissue by the inhaled dust, we have performed the various medical examinations such as chest radiography, pulmonary function test, high resolution chest CT, brnchoalveolar lavage and lung biopsy used bronchoscope and ultrathin bronchoscopy examination to 48 persons. The control group were 8 persons who did not exposed to dust, 40 cases of the experimental group have professionally exposed to the mineral dust. The results were as follows 1. The total number of cells in bronchoalveolar lavage was significantly increased in all of the pneumoconiosis group classified by chest and high resolution chest CT. 2. The composition rate of macrophage to the total number of cells in bronchoalveolar lavage fluid was significantly decreased in all of the pneumoconiosis group compared with the control group. 3. The composition rate of neutophils and lymphocytes to the total number of cells in bronchoalveolar lavage fluid was significantly increased in all of the pneumoconiosis group compared with the control group. 4. The forced expiratory volume in one second ($FEV_{1-0}$), maximal mid-expiratory flow (MMF), and maximal voluntary ventilation (MVV) were significantly increased only in the group of the progressed pneumoconiosis relatively. 5. We observed submucosal edema, anthracotic pigmentation and granuloma formation in transbronchial lung biopsy of the suspected pneumoconiosis (category 0/1) case which is thought to the early change of coal workers' pneumoconiosis.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.5
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• pp.668-676
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• 2018

This study has developed a technique to divide the aerosol optical depth of the entire aerosol (${\tau}_{total}$) into the dust optical depth (${\tau}_D$) and the pollution particle optical depth (${\tau}_P$) using the AERONET sun/sky radiometer data provided in Version 3. This method was applied to the analysis of AERONET data observed from 2006 to 2016 in Beijing, China, Seoul and Gosan, Korea and Osaka, Japan and the aerosol optical depth trends of different types of atmospheric aerosols in Northeast Asia were analyzed. The annual variation of ${\tau}_{total}$ showed a tendency to decrease except for Seoul where observation data were limited. However, ${\tau}_D$ tended to decrease when ${\tau}_{total}$ were separated as ${\tau}_D$ and ${\tau}_P$, but ${\tau}_P$ tended to increase except for Osaka. This is because the concentration of airborne aerosols, represented by Asian dust in Northeast Asia, is decreased in both mass concentration and optical concentration. However, even though the mass concentration of pollution particles generated by human activity tends to decrease, Which means that the optical concentration represented as aerosol optical depth is increasing in Northeast Asia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.219-225
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• 2020

In this study, the prototype of a blower was designed and made to develop a long-life blower with a volume flow rate of 10,000 ㎥/min with a required total pressure efficiency of 83% or more. Five experimental impellers with various lengths of dust deflectors were manufactured and used for the erosion experiments. The erosion test was conducted by operating for 160 hours in a self-produced closed loop-type erosion test apparatus. A prototype of a model blower was designed, fabricated, and tested. The results revealed a total pressure, air volume flow rate, and efficiency of 690.6 mmAq, 16,243.6 ㎥/min, and 83.6%, respectively, as the result of conversion to a blower based on the measured value of the blower model. The prototype was designed and fabricated as the experimental erosion equipment of the blower. A blower with a dust deflector was developed by performing the erosion experiments under harsh conditions. The blower showed an improved effect of more than 190% based on the wear thickness of the impeller compared to a conventional blower without a dust deflector.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.168-179
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• 1994

In some ceramic industries, worker exposure to dust, crystalline free silica and lead were determined and evaluated. The conclusions are as follows. 1. Crystalline silica in bulk samples was 10.5 % in sanitary ware industry, 9.4 % in tile industry, and 2.1 % in ceramic insulator industry respectively. The free silica content of air filter sample was 8.03 % in table ware industry, 5.59 % in sanitary ware industry, and 1.32 % in ceramic insulator industry. Because silica content in ceramic dust is relatively high, it is should be considered silica as important factor in evaluating for ceramic industry. 2. The silica contents in dust from tile, sanitary ware and table ware industries are above 5%, it should be classified as "Type" 2 dust. 3. The airborne concentration of respirable crystalline silica was $27.9{\mu}g/m^3$ in a sanitary ware factory and $5.8{\mu}g/m^3$ in a ceramic insualtor factory. Three of ten samples sampled the above factories were exceeded the occupational exposure levels, $100{\mu}g/m^3$. 4. Geometric mean(GM) of total dust in 11 factories was $1.00mg/m^3$ and GM of respirable dust concentration in 5 factories was $0.33mg/m^3$. Sanitary ware industry had the highest concentration of total dust, $1.62mg/m^3$ and of respirable dust, $0.88mg/m^3$. 5. Average lead concentration in air was $0.05mg/m^3$ in glazing process of 2 factories manufacturing table ware. Five of ten sample(50%) were exceeded $0.05mg/m^3$. Therefore lead exposure in pottery industry should be considered as important problem.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.1
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• pp.67-73
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• 2017

This study aimed to analyze the fluid inside the ceramic filtration dust collection system which was assumed to be a stationary 3-dimensional turbulence. The fluid dynamics data necessary for performance curves were obtained based on the analysis results. The governing equations used to compute the velocity distribution and pressure inside the catalyst converter were expressed with continuity and momentum equations. Furthermore, the ${\kappa}-{\varepsilon}$ turbulence model, already validated by the industry(coal factory, high temperature dust collector) was used for the study. Of a total of three computational models employed, Model-1 served as the basis for CFD analysis which took measurements in increments of 70mm.

• Journal of Korea Foundry Society
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• v.3 no.2
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• pp.100-105
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• 1983

The mechanism of coal-dust action on inhibiting burn-on of Sand to iron castings was taken in consideration by means of casting test and thermal decomposition test. To compare the ability of inhibiting sand burn-on, test castings were produced in green sand moulds added three different coal-rusts. And quantitative determination of lustrous carbon and volatiles production for coal-dust samples were performed.The lustrous carbon production was in good agreement with the casting test result. But total voltiles production was relatively inefficient on hibiting sand burn-on to test castings.The lustrous carbon theory can be given to explain the mechanism which coal-dust inhibits sand burn-on to iron castings.