• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.513-523
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• 2017

We evaluated the viability of phytoplankton along the salinity gradient in the flood and ebb tides of spring tide of February and the ebb tide of neap tide of March 2017 in the Seomjin River Estuary. Additional laboratory experiments were also conducted to determine the reason of the pH changes along the salinity gradient using the field natural sample in February. In field, saltwater was well mixed at downstream vertically and the salinity gradient was horizontally appeared toward upstream of freshwater zone. There were strong negative correlations between salinity and nutrient (nitrate + nitrite R=0.99, p<0.001, and silicate R=0.98, p<0.001), implying that those two nutrients of freshwater origin were gradually diluted with mixing the saltwater. On the other hands, relatively high phosphate concentration was kept in the stations of saltwater over 15 psu, indicating that it was caused by resuspended sediments of Gwangyang Bay and downstream by tidal water mixing.Among phytoplankton community structure in winter, Eucampia zodiacus have occupied to be c.a. 70 % in the most stations. Based on the field survey results for survivability of phytoplankton by phytoPAM instrument, there was positive correlations between salinity and chlorophyll a (R=0.82, p<0.001) and, salinity and active chlorophyll a (R=0.80, p<0.001), implying that the dominant marine diatom species may have significantly damaged in low salinity conditions of upstream. Also, maximum mortality rate of phytoplankton caused by low salinity shock was appered to be 75% in the upstream station. In particular, the pH in spring tides of February had tended to increase with high phytoplankton accmulated stations, suggesting that it was related with absorption of $CO_2$ by the photosynthesis of dominant diatom. In laboratory experiments, phytoplankton mass-mortality caused by low salinity shock was also occurred, which is confirmed with reducing the photosynthetic electron transport activity. Following the phytoplankton mass-mortality, bacteria abundance was significantly increased in 24 hours. As a result, the mass-proliferating bacteria can produce the $CO_2$ in the process of biodegradation of diatoms, which can lead to pH decrease. Therefore, marine phytoplankton species was greatly damaged in freshwater mixing area, depending on along the salinity gradient that was considered to be an important role in elevating and reducing of pH in Seomjin River Estuary.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.2
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• pp.94-99
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• 2011

Purpose: As the number of people enjoying skiing and snowboarding which are two popular winter sports has been increasing, wearing helmet during doing these sports has been needed for safety. The rates of head or face injury have decreased after using helmet. However the effect that wearing helmet has on cervical damage is not yet to be known. So through this research we intend to be helpful in developing effective program and safety equipment. Materials and Methods: During two seasons from December 2009 to march 2011, cased 658 cervical injuries within 14538 admittance in medical center of major resort due to skiing and snow-boarding injuries. For survey and research model, one year before the research year conducted a pilot study. Admittance were 432 male and 226 female, advanced 273 and 385 novice. We divided them into two groups depending on wearing helmet, measured cervical damage ratio and injury mechanism, and researched the severity of damage and diagnosed injury. Each group used SPSS 12.0 (SPSS Inc., Chicago, IL, USA) to process data statistically. Results: The number of patients was 312 in skier and 346 in snow boarder. Patients wearing helmet were 146 in skier and 127 in snow boarder. Classification of each injuries were confirmed as 292 cases of simple sprain, 359 bruising, 6 cervical fractures and 1 case of dislocation. Classification of injury mechanisms were 287 of human collision, 212 material collision, 108 of slip down by oneself, 39 of falling and 12 cases of etc. In cases wearing helmet ski 78/ snow board 70 were simple sprain, ski 64/ snowboard 68 were shown as bruising, ski 1/ snow board 2 had cervical fracture or dislocation. The ratio of cervical sprain increased in cases of wearing helmet compared to non-wearing cases and there was a statistical significance (p<0.001). The ratio of cervical contusion increased significantly in non-wearing helmet user (p<0.05). However, there was no significant increase in fracture and dislocation compared between helmet user and non-user (p> 0.05). Conclusion: In this study, wearing helmet had no relation to additional cervical injury occurrence or severity among skiers and snow boarders. The ratio of cervical sprain increased significantly in helmet user with person to person accident. However, the cervical contusion decreased. On this ground, further biomechanical studies are required and modified helmet will be necessary.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.346-352
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• 2020

It has been about 30 years since women students entered the Maritime College at Mokpo National Maritime University (MMU) and Korea Maritime & Ocean University to train as maritime seafarers. The women have been choosing a maritime college regardless of the Boarding Service Reserve System. Therefore, it is necessary to continuously study the motivation for admission, preferences for boarding, and desired career paths to guide the distinction and vision of maritime colleges. Accordingly, this study conducted a questionnaire survey on 93 women students attending the Maritime College at MMU. Of the respondents, 35.5 % said that they enrolled to become maritime officials and 30.1 % to become maritime seafarers. In addition to the current training for maritime seafarers, additional courses are required to train maritime experts. The study found that 88.2 % of the respondents thought that women's embarkation was more difficult than usual. It is considered that a systematic education program is needed for the onboard life of women maritime seafarers in schools and shipping companies. It was found that 69.6 % of the respondents preferred to embark as seafarers after graduation. After graduating from university, 32.3 % of the respondents said that they preferred to become navigation officers or engineers. It was also found that 24.7 % preferred to become marine-related civil servants / professionals, and 18.3 % preferred to become marine police. From the total, 83.9 % hoped for careers in marine-related fields. It is, therefore, necessary to organize courses and further education according to the motives for admission and preferred occupations of women students.

• Journal of Radiation Protection and Research
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• v.38 no.2
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• pp.106-118
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• 2013

In this paper, we analyzed the Cognition of irradiated food and its relation with self-efficacy. The most important variables described behaviors based on health choices compared with the choice to choose irradiated food items. According to the survey, 33.1% of respondents said that the reason why irradiated food is considered to be a health risk is because "radiation is dangerous". 27.9% of respondents answered that "eating irradiated food is like eating a radioactive substance", 21.1% said radiated food is comparable to a "genetic variation in food" while 10.1% said "food goes bad during the irradiation process". On this basis, it is reasonable to conclude that respondents have a misunderstanding of irradiated food without reference to the general theory of irradiated knowledge. In this respect, it would be helpful to provide education showing that irradiated food is not related to eating harmful or genetically modified food to help high school students create informed opinions of irradiated food. In terms of relevance with health-specific self-efficacy, experience of acquiring information about irradiated food was marked at r=0.148 (p<0.01), experience of purchasing irradiated food was marked at r=0.077 (p<0.05), experience of eating irradiated food was marked at r=0.113 (p<0.01) while knowledge of irradiated food, attitude towards irradiated food and behavior was marked at r=0.103 (p<0.01), r=0.076 (p<0.05) and r=0.105 (p<0.01) respectively. This shows that self-efficacy is high when one has experience of acquiring information about irradiated food, purchasing or eating irradiated food resulting in a high level of knowledge, attitude and behavior. Education which serves to improve the level of self-efficacy needs to be provided along with an educational program which will increase the public's understanding of irradiated food. It is expected that if this education which increases the level of self-efficacy is provided together with correct information of irradiated food, behavior to choose and eat irradiated food will also improve.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.750-763
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• 2018

This study conducted 10 sampling sites survey 4 times to determine the trophic structure and energy flow of marine ecosystems for Uljin marine ranching area, Korean East Sea from March to October 2013. Based on the ecological characteristics of biological species, one used the non-Metric Multidimensional Scaling method based on the similarity of species. A total of 19 classified species groups formed categories including, top predators, seabirds, large pelagic fishes, small pelagic fishes, rockfishes, pleuronectiformes, benthic fishes, semi-benthic fishes, cephalopods, benthic feeders, epifauna, bivalves, abalone, Cnidaria, zooplankton, benthic algae, microalgae, phytoplankton and detritus. The biomass, production/biomass, consumption/biomass, diet composition data of each species groups to input data used in Ecopath mode estimated the trophic structure and energy flow of marine ecosystems in the Uljin marine ranching area. One estimated each species groups on the trophic level from 1 to 5.687. The sum of all consumption was estimated at $229.7t/km^2/yr$ and the sum of all exports was as estimated $3,432.4t/km^2/yr$. Total system throughput was at $6,796.2t/km^2/yr$, and the sum of all production was estimated at $3,613.1t/km^2/yr$. Net system production according to these results was estimated at $3,490.3t/km^2/yr$ and total biomass (excluding detritus) was estimated at $167.3t/km^2/yr$ in the Uljin marine ranching area.

• Food Science of Animal Resources
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• v.27 no.2
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• pp.185-189
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• 2007

Animals must be inspected prior to and after slaughter to make certain they are free of diseases and unacceptable defects. Since meats are potentially hazardous foods, they should not be accept if there are any signs of contamination, temperature abuse, or spoilage. This survey was aimed to monitor the current situation of country-of-origin labels and sanitation for the meat markets in Seoul, Korea. The markets were divided into groups as to 25 territories in Seoul and the size of markets (large size, medium size, and small size). In terms of size distribution, small butcher shops occupied the highest percentage. On the itemized suitability test of unpacked and packed beer in Seoul, most butcher shops showed good evaluation. However, labels indicating the grade, storage and cooking instruction for unpacked beef were not properly posted on the products. The results of monitoring sanitation conditions for butcher shops in Seoul showed relatively low suitability. Especially, there were serious lack of knowledge about wearing the sanitation clothings, caps, and shoes. The problem with food safety is so complicated that producers, consumers, merchandisers, the press, the government and the scholar should try to solve the problems altogether. Also, it is important to educate and provide them with correct understanding and information for food hygiene and safety.

• Journal of Food Hygiene and Safety
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• v.23 no.4
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• pp.304-308
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• 2008

We investigated temperature management for refrigerated foods in large discount markets, department stores, and convenience stores. Eleven stores in the Seoul area were used to examine temperature maintenance for frozen and refrigerated foods, including soybean curds (tofu), fish surimi, mook, wet noodles, kimbab, and salads. The surficial and central temperatures of foods in a refrigerator and a freezer were examined. While the difference between the highest ($7.5^{\circ}C$) and the lowest ($6.4^{\circ}C$) temperature spaces in a refrigerator was $1.1^{\circ}C$, the corresponding difference between the highest ($8.9^{\circ}C$) and lowest ($7.5^{\circ}C$) food surface temperatures was $1.4^{\circ}C$. The average temperatures of both chilled food surfaces and refrigerator spaces were $7^{\circ}C$ (max. $22.9^{\circ}C$) and 8.2 degrees C (in. $-0.4^{\circ}C$), respectively. The temperatures of chilled food surfaces were $6.1{\times}10.6^{\circ}C$ for soybean curds, $6{\sim}12.3^{\circ}C$ for fish paste, $2.3{\times}18.2^{\circ}C$ for kimbab, $4.6{\times}12.2^{\circ}C$ for salads, $3.4{\times}12.6^{\circ}C$ for wet noodles, and $7.1{\times}19^{\circ}C$ for mook. Our results indicate that chilled foods require careful management for storage at temperatures below $10^{\circ}C$ with careful recording of the warmest area of the refrigerator.

• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.137-146
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• 2003

Objectives : Impaired hearing is a prevalent occupational hazard, not only in industry, but also in the armed forces. In military life, noise has unusual characteristics, and constitutes a serious hazard to hearing. The aim of this study was to analyze the hearing threshold data in order to compare the hearing loss among shipyard workers, representing different workers, and a military service background. Methods : A cross-sectional audiological survey, combined with a questionnaire study, was conducted on a stratified random sample of 440 shipyard workers, with long-term exposure to noise. The employees were divided into four groups, according to their working and military service backgrounds, in relation to their exposure to noise. Results : As expected, the working and military noise exposure group (Group I) had significantly poorer hearing than the other groups. The high frequencies (2-8 kHz) showed the greatest difference in terms of poorer fearing in both ears. The prevalence of noise-induced hearing loss (NIHL) was highest in Group I. A logistic regression analysis was applied to determine the dependence of the NIHL in relation to age, smoking, drinking, working duration, ear protection, past history of ear diseases, and working and military sonics backgrounds, on the noise exposure The important factors found to be related to the NIHL, in relation to noise exposure were: age, work duration, and working and military service backgrounds. The adjusted odds ratio estimates for NIML in the right ear were 4.5 times greater (95% CI 1.7-11.6) for the military noise exposed group, and 7.9 times greater (95% CI 2.0-31.3) for the working noise exposed group than in the controls. The hearing thresholds at the pure-tone average and 4 kHz were significantly increased with age and work duration with both the working and military service backgrounds. Conclusions : From these results, specific preventive programs were planned, which should be assessed by epidemiological surveillance of the military noise exposed population.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.459-467
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• 2020

In this study, we investigated the changes in both ambient temperature and microbial contamination of fresh convenience foods (FCFs) caused by the behavior of consumers after purchase. According to consumer survey results, it took 0.5 to 3 h put the purchased FCF in a home refrigerator or consume it. Only aerobic bacteria and Staphylococcus aureus (below maximum permitted limit) were detected in FCFs obtained from a local market. During storage of FCFs in a vehicle trunk for up to 3 h. the external and internal temperatures of FCFs were found to be 19 and 18.5℃ in spring, 44 and 42℃ in summer, 31.3 and 29.2℃ in autumn, and 17.6 and 16.8℃ in winter, respectively. Changes in contamination levels of aerobic bacteria on FCFs stored in a vehicle trunk for up to 3 hours are as follows: 2.72 → 3.41 log CFU/g in spring, 3.11 → 4.32 log CFU/g in summer, 3.08 → 3.81 log CFU/g in autumn, 2.71 → 3.36 log CFU/g in winter. S. aureus exceeding the tolerance was detected even when the FCFs were stored in a vehicle trunk for 1 h in summer and autumn and 2 h in spring and winter. Among three boxes (corrugated box, styrofoam box, and corrugated box coated with an aluminum film), the styrofoam box maintained the lowest temperature and showed the lowest growth rate of microorganisms on FCF after storage for 3 h in the vehicle trunk depending on whether ice was added. These results indicated that the possibility of food poisoning occurs when FCFs are exposed to the external environment. It is necessary to provide guidelines regarding storage temperature and allowable time for safe consumption of FCFs after purchase.

• Journal of Korean Home Economics Education Association
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• v.18 no.4 s.42
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• pp.173-192
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• 2006

The purpose of this study was to provide basic data for developing nutrition education program focusing on the health-oriented food choice and purchase which affect the adolescents' health. The data was collected by means of questionnaire from the total of 273 students who were living in cities and myun district and final 253 questionnaires were analyzed by using the SPSS/WIN 10.0 program. The results are summarized as follows. First, the major source of information on food was mass media, especially advertisement and students spent $20{\sim}30%$ of allowance on food purchase. The students purchased cookies or ice cream mainly, once every 2-3 days at the store near house, after school, for appeasing hunger or thirst. The influence of gender, mother's education level, economic status of family, the amount of allowance, the period of receiving allowance, the details of allowance recording, school location on food purchasing behavior were significant(p<.05). Second, the price and taste were the most important factors when the students purchase food. Nutrition and food sanitation/safety were considered less important by the students. The factors considered when the students purchase food were significantly different between Sender, father and mother's education level, and the amount of allowance(p<.05). Third, middle school students' food purchase behavior were influenced by advertizement, friends, parents. The influence of advertisement, friends, parents when the students purchase food were significantly different between gender, mother's career, economic status of family, and the amount of allowance(p.<05). From tile result of this study, the middle school students consider price and taste more than the other factors related nutrition and health in purchasing foods. Therefore, it will be necessary to develope and enforce nutrition education program focusing on how to choose and purchase safe, nutritious, delicious and cheap foot for adolescents.