• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.4
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• pp.339-343
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• 2011

This study is to examine the effect of freshwater influx on residence time to understand a long-term material transportation in enclosed bay. To predict the residence times of the coastal water in Masan bay, we were carried out the numerical simulations by using a EFDC model to simulate seawater circulation and particle tracking. The average residence times of Masan bay obtained from the particle release simulations under the condition to neglect a freshwater influx were estimated to be about 110 days in northern part of the bay to near Dotseom, 40 days in around Modo and 20 days in Budo to open sea. However, the average residence times under the condition consider with freshwater influx decreased about 81 days in both Region 1(northen Masan bay to near Dotseom) and Region II (Dotseom to Modo), but the Region III(Modo to Budo) and Region IV(Budo to open sea) incresed about 58 days and 17 days, respectively.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.115-122
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• 2016

The classical statistical approach using test data samples to estimate true value of Random Variables by calculating mean and variation (standard deviation or coefficient of variation) of samples is very useful to understand the existing condition of the structure. But with this classical approach, our prior knowledge through educational background and professional experience cannot provide any benefit to make decisions by the structural engineers. This paper shows the role of Bayesian methodology by providing chance of using valuable prior knowledge to come up with more accurate estimation of structural condition. This paper also shows how important it is to have a proper prior estimate of Random Variables and corresponding confidence level through gathering and studying more relevant information.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.157-164
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• 2016

For the hygienic production of oyster at Goseong bay, this study investigated the marine bacteriological condition of the area from 2008 to April 2009. Average seawater temperature and salinity ranged $2.8-19.3.0^{\circ}C$ and 32.61-34.91 psu, respectively. The coliform group and fecal coliform of seawater ranged < 1.8-4,900 MPN/100 mL and < 1.8-700 MPN/100 mL, respectively. The coliform group of oyster (Crassostrea gigas) ranged < 1.8-13,000 MPN/100 g. Fecal coliform of oyster ranged and < 1.8-310 MPN/100 g. Only one of 140 samples was exceeded in the U.S NSSP standard (> 230 MPN/100 g) of fecal coliform. Fecal coliform in seawater was on the level of clean sea, below the U.S. NSSP standards, and the contents of fecal coliform and heavy metals in cultured oyster were also below the U.S. NSSP, heavy metal standards, showing that the sea area is bacteriologically safe.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.352-357
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• 2018

In this paper, the improvement of the conductor temperature calculation algorithm is studied. The allowable current of the underground transmission line is determined by the conductor temperature limit. Usually to calculate the allowable current limit, the conductor temperature is assumed in the most worst environment condition. It is possible to increase the transmission capacity if the actual burial environment is considered. Therefore, in this paper an algorithm is proposed to calculate the conductor temperature by distinguishing two area of a underground transmission line condition - the manhole where the temperature sensor can be installed and the underground transmission line in which the temperature sensor can not be installed easily. When calculating the conductor temperature by the underground line in the pipeline, the existing standard describes each environment as a single soil heat resistance and one ambient temperature. In order to compensate this situation, thermal resistance model that can take into consideration the ground surface temperature and under ground temperature is proposed. It is shown that the accuracy of the proposed model is increased compared with the existing standard calculation result.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.137-143
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• 2015

Fire fighter are exposed to the situations which are hard to predict due to continuous and accidental changes which hinder their fire fighting activity. As these threats of safety accident act as fear factors, they are doing insecure fire fighting activities. Therefore, as unclear and abnormal risks of working environment such as the riskiness of expansion of disaster, instability, obstacles of activities, abnormality, urgency, etc. increase, safety accidents are caused. This study analyzes the actual condition of safety and health and awareness of fire fighter who are exposed safety accidents during their fire fighting activities and utilize such result as the basis data to secure safety of fire fighter, keep efficient safety control and prevent accidents. The results of analysis are as follows. As rescue works among all fire-fighting works shows the highest emotional stabilization and the highest post-traumatic stress disorder is shown in fire sergeant level positions, and fire fighters whose working period is 10-15 years, reinforcing safety training to long-term workers is necessary. As the result of survey regarding safety awareness, the highest awareness level was shown in fire sergeant level positions, and fire fighters whose working period is over 20 years, and when it comes to operation of fire fighting equipments, fire-fighting workers and workers having 1-4 years of working period showed high safety awareness. The more serious injury in a fire fighter experienced as the first injury after working as a fire-fighter, the more cause-and-effect relationship was shown between personal physical condition and work, and it is shown as obstacles of fire fighting activities and affects to post-traumatic stress disorder. Moreover, as after-work off duty activities also affect to official disaster, systematic improvement of working environment is required. Occupational medical work compatibility evaluation considering the distinct characteristics of works to secure fire-fighter' health care together with fire-fighting capability is shown to be necessary.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.1-10
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• 1998

This study has been carried out to lay out a scheme to increase the recreational functions of the forests through improvement of trail environment. To achieve the objective, environmental characteristics of the trails, actual condition of the users, and status of the park management were investigated in the suburb parks of Tokyo, Japan in 1996. As the results, the managing agency of investigated parks has been set itself to activate the use rather than environment conservation and improvement of recreational environment in forests. However, for taking into account the behavior and the purpose of visits in forest, the enhancement of scenic quality and amenity in the parks is a pressing need in recreational conditions. Therefore, to increase the recreational functions in forests, selection of courses and keeping of natural trails in good condition, control of users to ensure amenity, introduction of planting methods to enhance scenic quality and educational effects, and management to efficient conservation of nature ecosystem are required.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.369-378
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• 2010

School lunch programs at middle schools have increased in quantity. However, the quality of them is in fact not enough to reach the satisfactory standard, especially in the aspect of environment of school meals. It is true that there seems to be little attention to the environment. In this study, degree of satisfaction about school lunch program was surveyed for students in one middle school. Focus of survey was sanitary condition about the dining room and classroom where they have lunch. First, in order to investigate the degree of satisfaction about their dining place, questionnaire was sent out to the students at one middle school in Seoul. Questionnaire was made with reference to previous research. Second, for the study on environmental sanitation, dropping bacteria (general bacteria) is measured in three parts of dining place (entrance, serving table, dining table). Petriplate film was exposed to the responsible places for 15 minutes and then cultivated at the temperature of $32^{\circ}C$ for 48 hours before counting the number of bacteria formed. For the statistical analysis, SPSS 12.0 was used. The results of the study show that students had more satisfaction in dining room service than in classroom service. Important factors for the meal program such as "taste of food", "amount of food per student", "state of keeping warm", "appearance of food", "diversity of menu", and "kindliness of feeding staff" had more points in dining room than in classroom. For the environmental and sanitary aspect, the result of dropping bacteria (general bacteria) in dining room and classroom showed that table (5.00) and fooddistribution corner (8.67) of dining room were cleaner than those of classroom (P < 0.05). Making a good environment for school feeding will have a positive effect on the improvement of satisfaction and sanitation of school feeding. There should be expansion of dining room service for the students.

• Journal of KIISE
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• v.44 no.12
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• pp.1296-1306
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• 2017

Recently, as the number of Internet of Things users has increased, IETF (Internet Engineering Task Force) has released the CoAP (Constrained Application Protocol). So Internet of Things have been researched actively. However, existing studies are difficult to adapt to streaming service due to low transmission rate that result from buffer underflow. In other words, one block is transmitted one block to client's one request according to the internet environment of limited resources. The proposed scheme adaptively adjusts the rate of CON(Confirmable) message among all messages for predicting the exact network condition. Based on this, the number of blocks is determined by using buffer occupancy rate and content download rate. Therefore it improves the quality of user experience by mitigating playback interruption. Experimental results show that the proposed scheme solves the buffer underflow problem in Internet of Things streaming environment by controlling transmission rate according to the network condition.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.2
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• pp.153-161
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• 2011

Creating standards on thermal environment has been organized traditionally based on the youth and the manhood who are in mainly active layer of a society. However, traditional creating standards have differences from the physiology of the aged who have weak physical ability than younger person. As a result, it causes a health problem of the aged. Therefore, In this study, we had a basic study to create a comfortable thermal environment which had considered to a physical ability and a physiology of the aged, and build a ecological residence space to maintain health. We had several experiments with the aged; Experiment, Comfort Sensation Vote, Mean Skin Temperature and Analyzing HRV. The result have following by: 1)For the aged, the summer recommend temperature, $26^{\circ}C$, is appropriate within first 30 ~ 40 minutes, but it should be increasing the temperature after that time. 2) By considering PMV status and thermal feeling of the aged, they are prefer to higher temperature than normal setting of air-condition system. 3) In the condition of the summer recommend temperature, $26^{\circ}C$, they had answered in neutral or comfort with the comfort sensation vote. However, we had figure out that they had stress in a lower temperature by analyzing the result of HRV.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.131-138
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• 2006

In this study, the optimum condition of pH was investigated on the hydrogen gas production under anaerobic fermentation process. The results of the experiment showed that the optimum condition was observed at pH 6, resulting in 1175.87 mL/L of hydrogen gas production rate and 22.51% theoretical hydrogen conversion ratio. Hydrogen gas production rate and theoretical hydrogen conversion ratio were 901.77 mL/L and 17.48 % respectively at pH 5. At pH 7 and 8, the production rate of hydrogen gas was little low as 82.15 mL/L. Among the organic acids from the sucrose fermentation, propionate was observed as the dominant acid at pH 7 and 8 but butyrate was the dominant at pH 5 and 6.