• Journal of the Korean GEO-environmental Society
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• v.4 no.2
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• pp.77-91
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• 2003

The Hoek-Brown failure criterion for rock masses developed first in 1980 is widely accepted and has been applied in a variety of rock engineering problems including slope analyses. The failure criterion was modified over the years because rock mass strength by the original failure criterion in 1980 was overestimated. The modified failure criterion, named Generalized Hoek-Brown Failure Criterion, was proposed with a new classification called the Geological Strength Index(GSI) in 1994. Generally, Hoek-Brown failure criterion is applied in numerical analyses of rock mass behaviors using equivalent Mohr-Coulomb parameters estimated by linear regression method. But these parameters estimated by this method have some inaccuracies to be applied and to be incorporated into numerical models and limit equilibrium programs. The most important issue is that this method cannot take account of non-linear characteristics of Hoek-Brown criterion, therefore, equivalent Mohr-Coulomb parameters is used as constant values regardless of field stress distribution in rock masses. In this study, the numerical analysis on rock slope stability considering non-linear characteristics of Hoek-Brown failure criterion was carried out. Futhermore, by the latest Hoek-Brown failure criterion in 2002, the revised estimating method of equivalent Mohr-Coulomb parameters was applied and rock mass damage criterion is introduced to account for the strength reduction due to stress relaxation and blast damge in slope stability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.143-150
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• 1976

A trial has been made to find out a new method of calculating the survival rate of a fish Population utilizing the length composition data and the characteristics of the frequency curve of the length which usually is normal distribution curve. In this paper, a stochastic method is introduced and applied to calculate the survival rate of yellow croaker caught by Korean trawlers in the Yellow Sea and the East China Sea in 1971. The results are as follows : Mean of survival rate 0.46089 Variance 0.03073 Standard deviation 0.17529 95 percent confidence interval 0.36040-0.56138.

• The Journal of the Korea Contents Association
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• v.13 no.1
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• pp.115-126
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• 2013

The purpose of this study is to understand the utility of election campaign advertising by applying Q methodology that draw upon schematic model in subjectivity study. A survey was carried out among college students to classify the 16 selected Q-statements into a normal distribution using a 7 point scale. The collected data was analyzed using QUANL program, and principal component analysis using varimax rotation was used to identify the types of perceived utility of election campaign advertising. Type I can be categorized by a strong concern for the advertising technique improvement, Type II can be categorized by advocating for interest induction and Type III can be categorized by the truth inducement. The use of Q methodology provides insights into audience perceptions on the utility of election campaign advertising that would not be available through traditional methodologies and offers a foundation for audience involvement to address and overcome concerns about the utility of advertising for election campaign.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4337-4347
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• 2011

The purpose of this study is to analyze a research on the influence of consumers' purchasing selection criteria for golf-wear upon clothing pursuit benefit and purchase satisfaction. It selected people who are using golf games and golf courses in each city and county where are located in Gangwon-do Province, and surveyed targeting totally 206 people by using convenience sampling. As for data processing, the collected materials in this study were carried out frequency & percentage, reliability analysis, correlation & multiple regression analysis by using SPSS 13.0 program. The results are as follows. First, as a result of analyzing socio-demographic characteristics, the similar distribution was shown by gender with 51.0% in men and 49.0% in women. By age, the age group from their 40s to 50s was indicated to be the largest. The martial status was indicated to be a litter higher in the married with 57.3% compared to the unmarried with 42.7%. By healthy condition, what tends to be healthy can be known to be the largest with 79.4%. Second, positive correlation was indicated all in correlation of consumers' purchasing selection criteria for golf-wear with the clothing pursuit benefit and satisfaction. Third, as a result of analyzing on relationship of the golf-wear purchasing selection criteria with the clothing pursuit benefit, the purchasing selection criteria were indicated to have influence upon the ideal pursuit, the fashion & brand, comfort pursuit, and youthand-individuality pursuit, which are the clothing pursuit benefits. Fourth, the analytical result on the purchasing selection criteria for golf-wear with purchase satisfaction was indicated to have significant influence upon consumers' golf-wear purchase satisfaction.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.5
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• pp.316-325
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• 2010

Harmonic analyses are carried out in order to obtain the major frequency components of the air temperature (AT) and surface water temperature (SWT) data monitored in the Middle Area of the Yellow Sea (Yellow Sea monitoring buoy). The analysis shows the annual and semi-annual components are predominant and the higher frequency components are relatively weak with contribution to the short fluctuations, i.e. below $0.2{\sim}0.5^{\circ}C$, in the AT and SWT. The standard deviation of the AT residual is 2.4 times larger than that of the SWT residual and the occurrence frequency distributions of the AT and SWT residual components are both closely fitted to a normal-distribution function. The variation pattern on the AT-SWT plane forms the clear continuous hysteresis loop in anti-clockwise direction which is composed of the AT-SWT rising period, AT-SWT falling period, and the constant SWT period in winter season.

• Korean Journal of Environmental Biology
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• v.28 no.3
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• pp.115-124
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• 2010

In order to find out the short-term phytoplankton dynamics during summer season in Jinhae Bay, we investigated the environmental factors and phytoplankton population densities at 16 stations. A total of 66 phytoplankton species were appeared, diatoms occupied more than 80% of total species, and the others were dinoflagellates and raphidophyceaes. The dominant species were diatoms Chaetoceros affinis, C. didymus, C. pseudocurvisetus, Leptocylindrus danicus, Pseudonitzchia pungens, Skeletonema costatum and dinoflagellates Cochlodinium polykrikoides, Gymnodinium impudicum, Karenia mikimotoi, Prorocentrium minimum, Protoperidinium bipes and Scrippsiella trochoidea. According to multidimensional scaling (MSD) and cluster analysis based on phytoplankton community data from each station, the Jinhae bay was divided into two groups. The first group included stations in the inner part of Masan Bay, which is strongly influenced by high nitrogen loading and low salinity by river discharge. The second group included the other remained stations. Based on canonical correspondence analysis (CCA), small-size dinoflagellates K. mikimotoi, P. minimum, P. bipes and S. trochoidea and centric diatom C. pseudocurvisetus and S. costatum, which is dominanted in the inner area of bay, were related with DIN (ammonium, nitrate, nitrite). These results imply that the study area was grouped into the two water masses (inner and outer water of Masan Bay) and inner waters had higher phytoplankton abundances and Chl.a concentration than outer waters. As a result, summer phytoplankton peaks in the inner shallow bay were stimulated by increases in nitrogen and temperature.

• Toxicological Research
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• v.33 no.3
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• pp.239-253
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• 2017

Neodymium is a future-oriented material due to its unique properties, and its use is increasing in various industrial fields worldwide. However, the toxicity caused by repeated exposure to this metal has not been studied in detail thus far. The present study was carried out to investigate the potential inhalation toxicity of nano-sized neodymium oxide ($Nd_2O_3$) following a 28-day repeated inhalation exposure in male Sprague-Dawley rats. Male rats were exposed to nano-sized $Nd_2O_3-containing$ aerosols via a nose-only inhalation system at doses of $0mg/m^3$, $0.5mg/m^3$, $2.5mg/m^3$, and $10mg/m^3$ for 6 hr/day, 5 days/week over a 28-day period, followed by a 28-day recovery period. During the experimental period, clinical signs, body weight, hematologic parameters, serum biochemical parameters, necropsy findings, organ weight, and histopathological findings were examined; neodymium distribution in the major organs and blood, bronchoalveolar lavage fluid (BALF), and oxidative stress in lung tissues were analyzed. Most of the neodymium was found to be deposited in lung tissues, showing a dose-dependent relationship. Infiltration of inflammatory cells and pulmonary alveolar proteinosis (PAP) were the main observations of lung histopathology. Infiltration of inflammatory cells was observed in the $2.5mg/m^3$ and higher dose treatment groups. PAP was observed in all treatment groups accompanied by an increase in lung weight, but was observed to a lesser extent in the $0.5mg/m^3$ treatment group. In BALF analysis, total cell counts, including macrophages and neutrophils, lactate dehydrogenase, albumin, interleukin-6, and tumor necrosis factor-alpha, increased significantly in all treatment groups. After a 4-week recovery period, these changes were generally reversed in the $0.5mg/m^3$ group, but were exacerbated in the $10mg/m^3$ group. The lowest-observed-adverse-effect concentration of nano-sized $Nd_2O_3$ was determined to be $0.5mg/m^3$, and the target organ was determined to be the lung, under the present experimental conditions in male rats.

• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.527-540
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• 2020

While analyzing data, researching outliers, which are out of the main tendency, is as important as researching data that follow the general tendency. In this study we discuss the influence function for outlier discrimination. We derive sample influence functions of sample mean, sample variance, and sample standard deviation, which were not directly derived in previous research. The results enable us to mathematically examine the relationship between the empirical influence function and sample influence function. We can also consider a method to approximate the sample influence function by the empirical influence function. Also, the validity of the relationship between the approximated sample influence function and the empirical influence function is also verified by the simulation of random sampled data in normal distribution. As the result of a simulation, both the relationship between the two influence functions, sample and empirical, and the method of approximating the sample influence function through the emperical influence function were verified. This research has significance in proposing a method that reduces errors in the approximation of the empirical influence function and in proposing an effective and practical method that proceeds from previous research that approximates the sample influence function directly through empirical influence function by constant revision.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3487-3493
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• 2009

The degree of depression of dental hygienist was analyzed to reveal the various factors related to them. The self-administered between June 1st, and 30st, 2009, questionnaires were filled out from 221 dental hygienist in D City. 1.The distribution for depression degree has shown the rate as 79.1% in normal range group, 15.4% in mild depression group, 4.1% in moderate depression group and 1.4% in severe depression group, 2.As for depression, junior college, lower salary, poor sense satisfaction in work, not fit to the job, low personal relation with peer works or supervisors, poor subjective condition of health, without regular eating habits, without alcohol drinking, without regular exercise, in the group with higher level of job demand, lower job autonomy and lower supervisor support than their respective counterparts. 3.Concerning correlation between depression and various factors, while level of depression correlated with was negatively sense satisfaction, fit to the job, personal relation with peer works or supervisors, subjective condition of health, spervisor support, coworker support, it was positively correlated with job demand. Resulting from these results, in order to resolve depression properly, implementation and maintenance of program should be renewed to improve various kinds of factors.

• Food Science and Preservation
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• v.15 no.4
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• pp.556-561
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• 2008

This study was carried out to identify the cause of benzo(a)pyrene[B(a)P] production during the manufacture of sesame oil and perilla oil, and to minimize such B(a)P synthesis. The distribution of B(a)P in sesame seed and perilla seed differed with seed-growing district, the range was $0.06{\sim}0.31{\mu}g/kg$ in domestic seed and $0.12{\sim}0.47{\mu}g/kg$ in imported seed. B(a)P contents after roasting at $220^{\circ}C$ for 20 min in sesame seed and perilla seed were $1.87{\sim}2.47{\mu}g/kg$ and $2.12{\sim}2.43{\mu}g/kg$, respectively, and levels in oils obtained from the roasted seeds were $3.68{\mu}g/kg$ and $4.64{\mu}g/kg$, respectively. These data refer to seeds subjected to codsed roasting. With open roasting, the levels were $0.63{\mu}g/kg$ and $0.56{\mu}g/kg$, respectively. Closed roasting resulted in absorption of B(a)P, with consequent high levels in oils. We introduced forced ventilation during closed roasting. We tested various methods to remove B(a)P from sesame oil and perilla oil. Neither centrifugation nor filtering with diatomite and diatomiteactive carbon removed B(a)P. A filtering method using active carbon was effective. But this method adversely affected the color and flavor of sesame oil and perilla oil.