• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.255-258
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• 1999

Pneumoconiosis, very popular to coal miners who are exposed to coal dusts dominantly, was introduced in the 19th century to describe lung diseases consequent to the inhalation of mineral dusts. Coal workers' pneumoconiosis(CWP) colloquially called "black lung" in the United States, is a distinct pathologic entity resulting from the tissue reaction to deposits of dust include the coal macule, which associated with focal emphysema constitutes the characteristic lesion of simple CWP and complicated CWP or progressive massive fibrosis(PMF). Coal mining are also associated with chronic bronchitis, chronic airflow limitation, and/or generalized emphysema. Progressive massive fibrosis lesions may imprint on and obliterate airways and vessels, and cavitation is not uncommon, being the consequence of ischemic necrosis or mycobacterial infections. We report a case which is unusual form of progressive massive fibrosis to be differentiated from lung carcinoma. It is a rapid growing PMF with ischemic necrosis. By the studies which are about risk of having progressive massive fibroois, it is predicted to be 1.4%. And the other study shows that simple pneumoconiosis clearly predisposed to PMF, with five year attack rates of 13.9%, 12.5%, 4.4% and 0.2% among men with categories 3, 2, 1, and 0 respectively at the start of the risk periods.

• Explosives and Blasting
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• v.24 no.1
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• pp.63-69
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• 2006

Building tunnels means dealing with what rock is encountered. Relocation of the site of the underground structure is rarely possible. Tunneling engineers and miners have to cope with the quality of the rock mass as it is. Different tunneling philosophies and different rock classification methods have been developed in various countries. Most of the rock classification methods are based on the response of the rock mass to the excavation. Tunnel support requirements could be assessed analytically, supplemented by rock mass classification predictions, and verified by measurements during construction. Rock mass classifications on their own should only be used for preliminary, planning purposes and not for final tunnel support. Design of blast pattern in tunneling projects in Korea is also mostly prepared according to the general rock classification methods such as RMR or Q. They, however, do not take into account the blast performance, and as a consequence, produce poor blasting results. In this paper, the methods of general rock classification and blast design for tunnel excavation in Korea are reviewed, and efforts to develop a new classification method, reflecting the blasting performance, are presented.

• Korean Journal of Social Welfare
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• v.65 no.3
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• pp.79-106
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• 2013

The research intended to analyse gender identities of Korean male migrant workers in Germany through the biographical case reconstruction. Five cases were reconstructed and the following conclusions were drawn: A 'work-oriented identity of man as an individual' was formed through their biographies. And according to the terms of the interruptions and the discontinuities in their employment biographies, and in relation with their experiences of employment and marriage before migration, the 'work-oriented identity of man as an individual' was continuously or discontinuously reproduced in their experiences with welfare systems and social services in migration, as well as delayed or compressively differentiated in combination with a 'livelihood and household responsibilities sharing or sharing-exclusive identity of man as a husband' in their same experiences. Based on these results, some implications for the theory and practice of social work were addressed, furthermore some implications for the biographical research.

• Journal of Preventive Medicine and Public Health
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• v.24 no.1 s.33
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• pp.45-56
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• 1991

The history of occupational health in Korea s covered the era of the Republic of Korea after the Liberation from the Japanese colonialism. But the number of Korean workers exceeded about 2 millions at the times of liberation in 1945, so that it is expected that many occupational health problems inflicted Korean workers under the Japanese colonialism. The authors reviewed medical literatures, administrative documents, and other available data which were published under the colonial state, and collected things which had reference to the health status of Korean workers. The results were as follows : 1. Nutritional status of Korean workers was supposed to be inferior to that of general population, some students, and poor inhabitants in a remote mountain villages. 2. It was supposed that the constitution of Korean workers was near lower limit of average build of contemporary Koreans. 3. The accidents rate in mines was significantly high but decreasing year after year, and the most important cause of accidents was the fall of roof in the mine. The medical facilities and equipments for miners were supposed to be not sufficient in the mines and workshops. 4. Some occupational disease including silicosis, noise-induced hearing impairment, and decompression disease were known. But, overall incidence or prevalence of these diseases could not be identified. 5. On the whole, the fatalities of acute infectious diseases of Korean workers were higher than those of Japanese inhabitants in Korea and Korean inhabitants. The prevalence of pulmonary tuberculosis of Korean workers was increasing with every passing year. 6. The medical personnels and facilities were so deficient that most Korean workers were out of adequate medical use. We discussed only a part of the health status of Korean workers under the Japanese colonialism, so it would be necessary to have a better grasp of details of occupational health policy and health status in the era of afflicting.

• Geomechanics and Engineering
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• v.13 no.5
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• pp.861-879
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• 2017

Coal and gas outburst is a serious dynamic disaster that occurs during coal mining and threatens the lives of coal miners. Currently, coal and gas outburst is commonly predicted using single indicator and its critical value. However, single indicator is unable to fully reflect all of the factors impacting outburst risk and has poor prediction accuracy. Therefore, a more accurate prediction method is necessary. In this work, we first analyzed on-site impacting factors and precursors of coal and gas outburst; then, we constructed a Fisher discriminant analysis (FDA) index system using the gas adsorption index of drilling cutting ${\Delta}h_2$, the drilling cutting weight S, the initial velocity of gas emission from borehole q, the thickness of soft coal h, and the maximum ratio of post-blasting gas emission peak to pre-blasting gas emission $B_{max}$; finally, we studied an FDA-based multiple indicators discriminant model of coal and gas outburst, and applied the discriminant model to predict coal and gas outburst. The results showed that the discriminant model has 100% prediction accuracy, even when some conventional indexes are lower than the warning criteria. The FDA method has a broad application prospects in coal and gas outburst prediction.

• Journal of Magnetics
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• v.18 no.1
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• pp.43-49
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• 2013

A pulsed ferrite magnetic field generator (FMFG) was designed for the use in the 1000 m long through-the-earth (TTE) communication system for mining disaster situations. To miniaturize the TTE system, a ferrite core having 10,000 of permeability was used for the FMFG. Attenuation of the magnetic field intensity from the FMFG (200-turn and 0.18 m diameter) was calculated to be 89.95 dB at 1000 m depth soil having 0.1 S/m of conductivity. This attenuation was lower than 151.13 dB attenuation of 1 kHz electromagnetic wave at the same conditions. Therefore, the magnetic-field was found to be desirable as a signal carrier source for TTE communications as compared to the electromagnetic wave. The designed FMFG generates the magnetic field intensity of $1{\times}10^{-10}$ Tesla at 1000 m depth. This magnetic field is detectable by compact magnetic sensors such as flux gate or magnetic tunneling junction sensor. Therefore, the miniature FMFG TTE communication system can replace the conventional electromagnetic wave carrier type TTE system and allow reliable signal transmission between rescuer and trapped miners.

• Safety and Health at Work
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• v.1 no.1
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• pp.69-79
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• 2010

Objectives: Various cytokines induced by inhalation of coal dust may mediate inflammation and lead to tissue damage or fibrosis, such as coal workers' pneumoconiosis (CWP). Methods: To investigate the relevance of serum cytokines in CWP, the levels of serum interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-${\alpha}$) as CWP biomarkers in 110 retired coal miners (22 controls and 88 CWP subjects) were related to cross sectional findings and 1-year progressive changes of the pneumoconiosis. Progressive changes of CWP were evaluated by paired comparison of chest radiographs. Analysis by a receiver operating characteristic curve assessed the biomarker potential of each cytokine. Results: The mean serum IL-8 level was significantly higher in CWP compared to controls and IL-8 levels correlated with the degree of CWP. The median serum TNF-${\alpha}$ level was significantly higher in subjects with progressive CWP compared to subjects without CWP progression. The area under the ROC curve for IL-8 (0.70) and TNF-${\alpha}$ (0.72) for CWP identification and progression, respectively, indicated the biomarker potential of the two cytokines. Serum cutoff values of IL-8 and TNF-${\alpha}$ were 11.63 pg/mL(sensitivity, 69%; specificity, 64%) and 4.52 pg/mL (sensitivity, 67%; specificity, 79%), respectively. Conclusion: The results suggest that high levels of serum IL-8 are associated with the presence of CWP and those of serum TNF-${\alpha}$ are associated with the progression of CWP.

• Journal of Korean Society for Quality Management
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• v.48 no.4
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• pp.581-596
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• 2020

Purpose: purpose of this study was to propose the web application platform which can be to detect and discriminate various diseases and pest of tomato plant based on the large amount of disease image data observed in the facility or the open field. Methods: The deep learning algorithms uesed at the web applivation platform are consisted as the combining form of Faster R-CNN with the pre-trained convolution neural network (CNN) models such as SSD_mobilenet v1, Inception v2, Resnet50 and Resnet101 models. To evaluate the superiority of the newly proposed web application platform, we collected 850 images of four diseases such as Bacterial cankers, Late blight, Leaf miners, and Powdery mildew that occur the most frequent in tomato plants. Of these, 750 were used to learn the algorithm, and the remaining 100 images were used to evaluate the algorithm. Results: From the experiments, the deep learning algorithm combining Faster R-CNN with SSD_mobilnet v1, Inception v2, Resnet50, and Restnet101 showed detection accuracy of 31.0%, 87.7%, 84.4%, and 90.8% respectively. Finally, we constructed a web application platform that can detect and discriminate various tomato deseases using best deep learning algorithm. If farmers uploaded image captured by their digital cameras such as smart phone camera or DSLR (Digital Single Lens Reflex) camera, then they can receive an information for detection, identification and disease control about captured tomato disease through the proposed web application platform. Conclusion: Incheon Port needs to act actively paying.

• Convergence Security Journal
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• v.22 no.1
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• pp.121-127
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• 2022

Recently, social issues related to cryptocurrency mining are continuously occurring at the same time as cryptocurrency prices are rapidly increasing. In particular, since cryptocurrency can be acquired through cryptographic operation, anyone with a computer can easily try mining, and as the asset value of major cryptocurrencies such as Bitcoin and Ethereum in creases, public interest is increasing. In addition, the number of cases where individuals who own high-spec computers mine cryptocurrencies in various places such as homes and businesses are increasing. Some miners are mining at companies or public places, not at home, due to the heat problem of computers that consume a lot of electrical energy, causing various problems in companies as well as personal moral problems. Therefore, this study studies the technology to obtain evidence for the traces of mining attempts using the Windows artifacts of the computers that mined cryptocurrency. Through this, it is expected that it can be used for internal audit to strengthen corporate security.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.6
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• pp.613-623
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• 2013

As Limestone mines have been operated with various environmental, societal and managemental problems depending on their characteristics and developing methods, many great efforts have been applied to solve these problems. Installing the mining facilities underground is one of the successful efforts to keep the sustainable limestone mine development. This effort could reduce these problems. However, unfortunately it made an side effect of constructing a large underground space in mining site. Moreover, this space caused a necessity of various disaster managements for the safety of workers and facilities. This study introduces the priority list of a limestone mining process if there are disasters in underground mining site. This result is coming from the risk assessment and business impact analysis on survey data which were obtained from the miners of that particular limestone mine. According to the result, the highest risk is 'disregard of safety guidelines in crushing & classifier process'. The result also shows the highest priority business, above all things, is 'a pit linked work of in & out process'.