• Geomechanics and Engineering
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• v.24 no.6
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• pp.519-529
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• 2021

In coal mining activities, the abutment stress of the coal has to undergo cyclic loading and unloading, affecting the strength and seepage characteristics of coal; additionally, it can cause dynamic disasters, posing a major challenge for the safety of coal mine production. To improve the understanding of the dynamic disaster mechanism of gas outburst and rock burst coupling, triaxial devices are applied to axial pressure cyclic loading-unloading tests under different axial stress peaks and different pore pressures. The existing empirical formula is use to perform a non-linear regression fitting on the relationship between stress and permeability, and the damage rate of permeability is introduced to analyze the change in permeability. The results show that the permeability curve obtained had "memory", and the peak stress was lower than the conventional loading path. The permeability curve and the volume strain curve show a clear symmetrical relationship, being the former in the form of a negative power function. Owing to the influence of irreversible deformation, the permeability difference and the damage of permeability mainly occur in the initial stage of loading-unloading, and both decrease as the number of cycles of loading-unloading increase. At the end of the first cycle and the second cycle, the permeability decreased in the range of 5.777 - 8.421 % and 4.311-8.713 %, respectively. The permeability decreases with an increase in the axial stress peak, and the damage rate shows the opposite trend. Under the same conditions, the permeability of methane is always lower than that of helium, and it shows a V-shape change trend with increasing methane pressures, and the permeability of the specimen was 3 MPa > 1 MPa > 2 MPa.

• Geotechnical Engineering
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• v.6 no.1
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• pp.43-58
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• 1990

In order to get ultimate pullout resistance of ground anchor, the position of failure surface, normal stress and friction angle on the failure surface should be known. In this study, the position of failure surface is obtained by observing deformation of ground around anchor, and stresses on the anchor surface are analyzed by measuring normal and shear stresses on the anchor surface through model anchor test in plane strain. In addition, the relationship between lateral earth pressure and the position of failure surface is analyzed and the formula for calculating ultimate pullout resistance of anchor is proposed by using non-dimensional coefficient of ultimate pullout resistance.

• The Korean Journal of Emergency Medical Services
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• v.11 no.3
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• pp.65-79
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• 2007

Purpose : It was to find out demand and supply of EMT from 2007 to 2045 and to expand scope of practice of paramedic in Korea. Methods : This study was conducted by applying a projection formula to the data from admission quota for EMT of the Ministry of Education & Human Resources Development, rate of successful candidates of annual report of the National Health Personnel Licensing Examination Board etc. Results : The number of EMTs were 6,043 paramedics, 5,378 EMT-Bs until 2006 and two produce constants derived from simple estimation were paramedic 0.81, EMT-B 0.86. On the American basis of 5.6 EMTs per 10,000, the number of paramedics under the present act will reach the basis around 2015(5.02), the number of paramedics under the amended act will reach the basis around 2030(5.50). Conclusion : There was relationship between scope of practice of paramedic in the act and demand-supply of paramedic, this necessitates surveys, studies, amendment of the act, legalization for expanded scope of practice of paramedic.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.795-807
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• 2020

The more liquid the capital market, the more attractive it will be for investors to place their money in the capital market. Therefore, the purpose of this study is to investigate the factors that influence stock liquidity of manufacturing sector companies listed on the stock exchange in Indonesia. The independent variables used in this study are forward-looking information disclosure, institutional ownership, foreign ownership, and board activity with information asymmetry as an intervening variable and stock liquidity as the dependent variable. The population of this study is manufacturing sector companies listed on the Indonesian stock exchange (IDX). Samples are selected based on the random sampling method, and the number of samples is calculated based on the Slovin formula. The sample was 59 manufacturers, and data was annual reports (for 2 years) and stock transactions from 2016 to 2017. The results of the study showed that forward-looking information disclosure had a significant effect on information asymmetry. Information asymmetry and foreign ownership have a significant impact on stock liquidity, whereas information asymmetry mediates the relationship between forward-looking disclosures and stock liquidity. Furthermore, the accuracy of information about the certainty of business activity both now and in the future can instill confidence in stakeholders in interacting and cooperating.

• Journal of the Korea Society of Computer and Information
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• v.9 no.3
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• pp.135-141
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• 2004

With the diversified and enlarged softwares, the issue of software maintenance became more complex and difficult and consequently, the cost of software maintenance took up the highest portion in the software life cycle. We design Reverse Engineering Tool for software restructuring environment to object-oriented system. We design Rule - Based Reverse - Engineering using Class Information. We allow the maintainer to use interactive query by using Prolog language. We use similarity formula, which is based on relationship between variables and functions, in class extraction and restructuring method in order to extract most appropriate class. The visibility of the extracted class can be identified automatically. Also, we allow the maintainer to use query by using logical language. So We can help the practical maintenance. Therefore, The purpose of this paper is to suggest reverse engineering tool and evaluation reverse engineering tool.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.445-450
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• 2001

This study was carried out In Investigate the correlation between toluene In air and hippuric acid In human urine, which 1.: based on the results of the health check-in and the measure of working environment, was investigated for two years. The concentration of toluene in air for the five working places in Yang-San area were ranged from 39.05±10.31 ppm to 4.04±3.38ppm and the mean value of those was 16.89±14.76ppm. The mean value was 16.89±14.76ppm which is below the permissible limit of toluene. The concentration of hippuric acid(HA) In the worker's urine were between 0.47g/ℓ and 0.76g/ℓ. There was mutual correlation (Υ=0.94) between the concentration of toluene in air and that of hippuric acid in urine. In case of male workers, the mean value of hippurlc acid In urine was 0.56g/ f and the female workers was 0.57g/ℓ that showed higher than the male's. However, there was no relationship between the workshop and the distinction of sex. From the mean value of toluene in air(T) and that of hippuric acid(H), we obtained the formula, Η=0.3logΤ+0.235.

• The Research Journal of the Costume Culture
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• v.4 no.3
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• pp.395-406
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• 1996

This article aims, by analyzing structurally the codification of dress sign in Korean society, the signifying system of the codes and their message communicated, to make clear a signifying structure that would be codified through the relationship between abstract concepts and real condition of dress. I used the semiotic theory of Ferdinand de Saussure′s conception on structuralismly the codification, cultural semiology of Roland Barthes and Myung-Sook Han′s formula of dress structure as tools analyse may objective of wedding dress of folks in Choson Dynasty, which has been successive our traditional Korean wedding dress. My results of the study are : The procedure of wedding ceremony in Choson Dynasty was presented in texts like Juga-garye, Sarye-peonram and Kukjo-orye, its dress system has been more emphasized on language, and aspect of social system, than parole, one of individual realization. In addition, the meanings of marrage such as "Oneness of bride and bridegroom", "Mixture of two sexes", "Blessing of good luck", were included in the signified like the style, pattern and color of the wedding dress, and specially, pattern and color, the articulated morphemes, was emphasized, When we combinated terms of dress in Choson Dynasty with syntagmatic, regarding their list as paradigmatic, it will signify a wedding dress, and according to combinating ways, it amy be divided as sign of dresses of bride and bridgeroom by sex or king, gentry and common people by class. Wedding Dress in Choson Dynasty = [{ODx(U/Dxu/d)}+AC·H·FW].

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.393-403
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• 2019

The water-storage performance of an intake weir can be evaluated by stage-discharge ratings. The stage-discharge rating of a gabion weir depends on the physical characteristics of the filling materials. This study reviewed existing discharge formulae for the evaluation of the water-storage performance of gabion weirs. A previously published relationship between the characteristics of filling materials and experimental constants was adapted for stage-discharge rating. The mean size of the filling material is the most influential factor for the water intake and water-storage performance of gabion weirs.

• Journal of the Korean Institute of Navigation
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• v.9 no.1
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• pp.41-81
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• 1985

Tidal phenomenon can be utilized by the wise and cautious mariner to safely perform his duties as pilot and navigator. It can be either a help or hindrance to the mariner. The principle of MULDAE which expresses the determination of the state of the tide based upon knowledge of the lunar date and it has been used in Korea since ancient times. The folk method of calculation was essentially based on an unsystematic division of the lunar month, traditionally using the numbers 7 or 8. As the lunar cycle is complete in 15 days the tidal cycle should also correspondence closely to the lunar date. This paper represents the first scientific attempt to systematically investigate this unique traditional method of tidal calculation and contains a comparison of the MULDAE and ordinary (solar based) tide calculation methods. MULDAE was compared with the standard tide table for standard and island ports in Korea from 1982 to 1985. This study concluded that MULDAE was indeed an accurate adn reliable predictor of tidal activity. Furthermore, the number 6 was found to be the correct divisor upon which to base MULDAE calculations Also a formula expressing MULDAE as a function was discovered. This research show that MULDAE can be applied nationwide and is a reliable and easy way to predict tides based upon mean figures for certain ports and island A calender showing MULDAE is presented here for the first time. A clear relationship between the MULDAE method of calculating tides and the use of ordinary tide tables is proven.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.644-656
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• 1984

In Tetralogy of Fallot, the most common congenital cyanotic heart disease, the mortality is decreasing continuously with adequate type and timing of operation. At S.N.U.H., 195 patients were operated from January 1982 to December 1983 and 176 patients among them were analysed in the view of pre-operative pulmonary arterial condition measured by cardiac cineangiogram. The most common associated anomaly was PFO and ASD and they did not affect the postoperative course and mortality. The overall mortality rate was 8.5% in 1982 and 6.8% in 1983 but under 2 years of age, the mortality rate was relatively high as 25% in 1982 and 16.7% in 1983, and when transannular patch widening of Right Ventricular Outflow Tract was used, the mortality rate was 12.5% in 1982 and 27.3% in 1983. Preoperative angiographic measurements of the pulmonary arterial status for prediction of the ratio between the Left Ventricular and Right Ventricular peak systolic pressure were calculated retrospectively according to the Blackstones formula, and the predicted value of PRV/LV greater than 0.6 carried apparently high complication and mortality rate as 16.6% M.R. in 1982 and 11.1 % in 1983. Among postoperative complications, c-RBBB occurred most frequently about 50% but did not influenced to mortality, Low Cardiac Output Syndrome was developed in about 40%. If we select the patient who should have the staged operation including shunt operation and choose the type of RVOT relief, we expect the improvement of postoperative clinical results.