• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.26-32
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• 2017

Enlargement and speed-up of a ship and diversification of ship's type have served to greatly increase the importance of marine transport means. It's reported that accident occurrence frequency of collision is high next to engine damage among the ship accident types, and that the accident ratio according to human factors is also high. In addition, ship accidents come to occur caused by complex cause factors rather than a sole cause factor, it is necessary to investigate the cause factors through the written verdict. This study proposed the cause factors of collision ship accident on the basis of human factors in collision ship accident among the written verdicts provided by the Korean Maritime Safety Tribunal, and inquired into the cause factor and effect through the correlation analysis of accident occurrence factors. Also, this study predicted the collision accident through analyzed the major cause factor of the occurrence at the zero minute when collision on the basis of the time taken from the time point of detecting collision of ships to the time point of collision occurrence. This study used commercial software-Statistical Package for Social Sciences (SPSS Ver21.0) to do correlation analysis. For time analysis, this study analyzed the cause factor and time by analyzing the time taken from the time point of detected ships to the time point of collision occurrence on the basis of the written verdicts. The study analysis showed that there were many cases of collision ship accidents occurrence caused by more than two sorts of cause factors, and that the case (zero minute) where there is no time to spare for collision avoidance accounted for 36.1 %, and negligence in guard or surveillance of the other ship, and sailing while drowsy, or drinking was a contributor to an accident. Poor watch keeping is very strong relationship with pool ready for sail.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.404-410
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• 2014

In this study, we conducted an analysis of the drumming bioacoustics of three woodpeckers typical to South Korea. The targeted species were, from largest to smallest in size, the Black Woodpecker(Dryocopus martius), the Great Spotted Woodpecker(Dendrocopos major) and the Japanese Pygmy Woodpecker(Dendrocopos Kizuki). The drumming sounds of these three species of woodpeckers were recorded and analyzed. Sound recordings were taken in the Guryongsa Valley, Chiaksan National Park and on the campus of Sangji University, Wonju City, South Korea. Drumming recordings were obtained in the following manner. As researchers walked along trails in the investigation areas, when woodpecker drumming sounds were indicated, positive identification of the species was made using binoculars then the recording of the drumming sound was started. The average time per drumming, in seconds, was Black Woodpecker(D. martius) 1.614 seconds, Great Spotted Woodpecker(D. major) 0.683 seconds and Japanese Pygmy woodpecker(D. Kizuki) 0.200 seconds. The average number of strikes for each drumming was Black Woodpecker(D. martius) 31.2 times, Great Spotted Woodpecker(D. major) 14.9 times and Japanese Pygmy Woodpecker(D. Kizuki) 6.7 times. The strike speed, in strikes/sec, for each species was the Black Woodpecker(D. martius)19.3strikes/sec, the Great Spotted Woodpecker(D. major) 21.8strikes/sec and Japanese Pygmy Woodpecker(D. Kizuki)33.3strikes/sec. The frequency of drumming, in Hertz, was Black Woodpecker(D. martius) 776.9Hz, Great Spotted Woodpecker (D. major) 1,213.8Hz and Japanese Pygmy Woodpecker(D. Kizuki) 826.0Hz. In interpreting this data, Analysis of Variance (ANOVA) was used and it was determined that there was a significant statistical difference between species in drumming duration, time and interval of striking. The findings support that the bigger the biomass of the woodpecker, the longer the drumming duration and striking time. However, the smaller the size of the woodpecker, the faster the strike speed. A correlation between body type size and drumming characteristics was clearly identified. As for strike frequency, measured in Hertz, the medium sized Great Spotted Woodpecker's (D. major) frequency was high whereas the Black Woodpecker(D. martius) and Japanese Pygmy Woodpecker's(D. Kizuki) frequency was similar. A clear trend in reference to body size on this measure does not exist.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1335-1343
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• 2013

Parents in South Korea are known for their high level of educational zeal for their children. As a result, their children usually take extra classes in institutions as well as participate in other extracurricular activities such as sports and music. The purpose of this study was to examine the lifestyle and dietary behaviors of Korean elementary students involved in such activities. The total number of subjects was 550 fourth to sixth graders in elementary schools in Sejong, Korea. Of the total subjects, 88.0% were involved in extracurricular classes or other activities for an average of 7.34 hours/week. The subjects were assigned to one of four groups based on the degree of extracurricular activities: No extra-class (n=66), Low extra-class (1${\leq}$taking time<5 hours/week, n=118), Medium extra-class (5${\leq}$taking time<10 hours/week, n=184), and High extra-class (taking time${\geq}$10 hours/week, n=182). More subjects in the High extra-class group went to bed late (P<0.01), were under stress (P<0.01), and skipped breakfast, compared with those in the other groups. The ratio of students who answered 'I go to an institute without a meal' (P<0.01), 'I prepare a meal for myself' (P=0.053), or 'I eat out before going to an institute' (P<0.01) was higher in the High extra-class group than in the Low extra-class group. The frequency of eating fast food was higher in the High extra-class group, compared with the other groups. These results indicate that a high amount of extracurricular studies may have a negative effect on the children's lifestyles and dietary behaviors. Therefore, this study alerts parents to the potential harm of excessive extracurricular activities to their children's health.

• Geophysics and Geophysical Exploration
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• v.1 no.2
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• pp.127-135
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• 1998

The Born approximation is widely used for solving the complex scattering problems in electromagnetics. Approximating total internal electric field by the background field is reasonable for small material contrasts as long as scatterer is not too large and the frequency is not too high. However in many geophysical applications, moderate and high conductivity contrasts cause both real and imaginary part of internal electric field to differ greatly from background. In the extended Born approximation, which can improve the accuracy of Born approximation dramatically, the total electric field in the integral over the scattering volume is approximated by the background electric field projected to a depolarization tensor. The finite difference and elements methods are usually used in EM scattering problems with a 2D model and a 3D source, due to their capability for simulating complex subsurface conductivity distributions. The price paid for a 3D source is that many wavenumber domain solutions and their inverse Fourier transform must be computed. In these differential equation methods, all the area including homogeneous region should be discretized, which increases the number of nodes and matrix size. Therefore, the differential equation methods need a lot of computing time and large memory. In this study, EM modeling program for a 2D model and a 3D source is developed, which is based on the extended Born approximation. The solution is very fast and stable. Using the program, crosshole EM responses with a vertical magnetic dipole source are obtained and the results are compared with those of 3D integral equation solutions. The agreement between the integral equation solution and extended Born approximation is remarkable within the entire frequency range, but degrades with the increase of conductivity contrast between anomalous body and background medium. The extended Born approximation is accurate in the case conductivity contrast is lower than 1:10. Therefore, the location and conductivity of the anomalous body can be estimated effectively by the extended Born approximation although the quantitative estimate of conductivity is difficult for the case conductivity contrast is too high.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.291-302
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• 2019

In this paper, we first looked at the structures and characteristics of the musical instrument to study the tone of haegeum, which is the only Korean musical instrument made using all the eight ingredients that make gugak instruments, and which is now the most frequently used in fusion gugak or pop music production sites. In addition, for the comparison of the various tones of the haegeum, under the same conditions, we analized how the haegeum's tone changes according to the types of Wonsan, which works as the bridge of the haegeum. Four Wonsan made of Park, Rosewood, Maple and Black Dan were used in the experiment, and low, medium, and high notes were recorded to compare the inner and outter open strings and the sound ranges. By doing so, we looked at the composition of frequency characteristics and the distribution and analyzed the timbres according to the types of Wonsan. Based on this study, it is expected to help the performers in the field choose the proper Wonsan according to each harmony part, rather than just to their tastes when performing Gugak orchestral music or haegeum ensemble. We also look forward to playing haegeum and using the timbres in various combinations of Wonsan that suit the genres at the pop music industry.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.91-99
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• 2011

Risk ranking must be determined for various hazards/food combinations to conduct microbial risk management effectively. Risk Ranger is a simple, easy-to-use calculation tool developed in Microsoft Excel and designed to rank the risk (low, medium, and high) for semi-quantitative microbial risk assessment. The user is required to answer 11 questions in Risk Ranger related to 1) severity of the hazard, 2) likelihood of a disease-causing dose of the hazard being present in the meal, and 3) the probability of exposure to the hazard in a defined time. This study determined the risk ranking for twenty three combinations of foodborne pathogens/potentially hazardous foods (PHFs) using a Risk Ranger. In this study, pathogenic E. coli in fresh cut produce salad was scored as 79, which was the highest rank among the 23 combinations of the foodborne pathogens and PHFs. On the other hand, zero risk was obtained with V parahaemolyticus in sushi, Salmonella in meat products and E. coli O157:H7 in hamburger patties. Although Risk Ranger is very simple method to rate the risk of foodborne pathogens and PHFs combination, the accuracy of result was mainly affected by the availability and accuracy of data in the literature. According to the result of literature review, the data are needed for contamination rate of raw materials, consumption amount/frequency of PHFs, and the effect of processing on pathogen. Risk ranking must be continuously revalidated with new data.

• Korean Journal of Environment and Ecology
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• v.22 no.1
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• pp.43-58
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• 2008

For this study, which was conducted in the summer from $2004\sim2007$, 10 small and medium sized streams in Korea were selected(Munsan and Gokreung Stream in the Han River watershed, Mi, Ssanggye and Nam Stream in the Nakdong River watershed, Gapeong and Jojong Stream in the Bukhan River watershed, Cheongmi, Yanghwa and Bokha Stream in the Namhan River watershed), and plant surveys were performed using the belt transect method on the most natural 1km sections of each stream in order to clarify the natural environment condition of the plants in each stream. In the results of the plant survey, the total number of plant species recorded was 296. After selecting 121 species of those surveyed plant in order of frequency, an RDA(Redundancy Analysis) and a Pearson Correlation Analysis were performed to determine the correlation between the selected plant species and environmental factors( such as distance from channel, size of bed material, number of bars, altitude, bed slope, width of channel, and measured data of water quality) of the study sites. There was no significant correlation between the 121 plant species and altitude, bed slope, and number of bars at the research sites, but the correlation of plant species with size of bed material, width of channel, electrical conductivity, and phosphate$(PO_4-P)$ concentration was from very high to moderate. Also, the spectrum of these plant species reflects the actual environmental conditions so the method used in the study seems to be correct, but owing to the range of diversity, the results of the study seem to be difficult to extend to other streams. Nevertheless, it is expected that this data can be used as a basic material for researching plants by stream characteristics or in selecting plant species for streams.

• Journal of Korean society of Dental Hygiene
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• v.22 no.1
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• pp.1-9
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• 2022

Objectives: This study was conducted to find scaling patients' oral health belief and satisfaction by applying Comprehensive Dental Hygiene Care (CDHC) process. Methods: From July 1 to September 20, 2020, the data about 182 patients who had scaling in dental clinics and hospitals had been collected and analyzed. For data analysis, SPSS Statistics 22.0 was applied to conduct frequency analysis, chi-square, t-test, One way ANOVA and Pearson's correlation analysis. Results: Regarding oral health behavior, in the CDHC group 92.4% used oral care products (p<0.001), and 67.4% regularly visited dental clinics for oral care (p<0.001). Regarding the oral health belief according to general characteristics, in the CDHC group, persons aged '50-65' scored 2.4 (the highest), and were significantly different from those aged '20-29' as the result of post-hoc analysis (p<0.001). Regarding the oral health belief of the CDHC group according to oral health behavior, the scaling cycle '3 months' scored the highest (p<0.05). The patients' satisfaction had high correlations with benefit (p<0.01) and Importance (p<0.05) as the sub factors of the oral health belief of the CDHC group. Conclusions: CDHC positively influenced scaling patients' oral health belief and satisfaction. Therefore, it is necessary to expand CDHC, as the medium to improve oral health belief and satisfaction, to clinical settings.

• Journal of Korea Entertainment Industry Association
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• v.15 no.3
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• pp.289-295
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• 2021

Today, the most important factor affecting the quality of human life is thought to be due to the environment. The importance of environmental monitoring systems to improve human life and improve welfare as the magnitude of the damage increases year by year due to the rapid increase in the frequency of hail, typhoons, collapse of incisions, landslides, etc. Is increasing day by day. Among environmental problems, problems caused by water quality have a very high proportion, and as there is a growing concern that the scale of damage will increase when water pollution accidents occur due to urbanization and industrialization, the demand for social water safety nets is increasing. have. In the last 5 years, 259 cases of water pollution (Han River 99, Nakdong River 31, Geum River 25, Seomjin River and Yeongsan River 19, and 85 others) have occurred in the four major river basins. Caused damage. Therefore, it is required to establish a water quality environment management strategy system based on big data that can minimize the uncertainty of the water quality environment by expanding the target of water quality management from the current water quality management system centered on the four major rivers to small and medium-sized rivers, tributaries/branches, and reservoirs. In this paper, we intend to construct and analyze a water quality monitoring system based on big data that can present useful water quality environment information by analyzing the water quality information accumulated for a long time.

• Korean Journal of Hospice Care
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• v.7 no.1
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• pp.15-28
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• 2007

This study was focused on figure out what kinds of elements are influencing on job satisfaction with approach of the educational system. It was also to figure out how work characteristics and role conflicts of employees influence on job satisfaction. Objects of study were employeeswho had been working in Hospice and Palliative medical center at least for 6 months, and they were doctors, nurses, ministers, and welfare workers. Collected materials were analyzed by Frequency Analysis, One-way ANOVA, Correlation Analysis, and SimpleRegression Analysis. Results from study can be summarized like below. The first, job satisfaction of workers in Hospice and Palliative medical center were 3.36, and this numerical value is pretty high over all. For saying from the higher to the lower satisfaction level, there were satisfaction with job itself, satisfaction with co-workers, satisfaction with seniors (superiors), and satisfaction with organizations, on the other hands, satisfaction with salaries was turned out as the lowest level among those. The second, role conflict was 2.63, and it is considered as the medium level. after inquiring into it by elements of role conflict, they felt many environmental difficulties compared to other workers in different fields such as environmental difficulty, role ambiguity, insufficient ability, process obscurity, etc. The third, work environment influencing on job satisfaction are as follows. Professional environment among characteristics of work environment was significant statistically. Job satisfaction of ministers was the highest; others were in the order of doctors, welfare workers, and nurses. For employment history, job satisfaction was higher as they have more and longer job experience including whole professional experience both in hospice and palliative medical center. In addition, participating in hospice and palliative programs, intensive training regularly was significantly. Job Motivation was also significant statistically. Especially, job satisfaction was higher when people decided to work in hospice and palliative medical center because of individual desire (self-realization). Lastly, influence of role conflict on job satisfaction is as follows. Environmental difficulty, role ambiguity, insufficient ability, process obscurity, etc showed the significant meaning statistically, and the lower role conflict was related with the higher job satisfaction. Suggestions for next study based on such results are as follows in order to improve or increase job satisfaction of employees in hospice/palliative medical centers. The first, to expand education opportunity of employees is needed to increase job satisfactionof hospice/palliatives medical centers. Participating in intensive programs and seminars by types of occupation and acquiring professional knowledge are very important since employees are motivated by those activities. For that, developing and activating intensive education/programs by professional occupations are suggested. The second, dividing roles of employees and determining each job's limit clearly in hospice/palliative medical centers are required. For that, study developing standard job regulations is suggested for each professional job. Lastly, developing and providing reasonable salaries is needed because low salaries of hospice/palliative medical centers are the absolute reason lowering job satisfaction. Therefore, this paper suggests improving the salary level of employees of hospice/palliative medical centers and developing practical plan for it.