• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5060-5065
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• 2012

The purpose of this study was to report the incidence of drowning accident in order to prevent and decrease the accidents of drowning. Data were obtained on all accidents of drowning accidents occurred from January to December 2007 were identified by using the Emergency Activity Daily Report Data from the National Emergency Management Agency (NEMA). The age, weather, date, location, time and case of the drowning accident were examined. The Chi-square test was used to compare each group. All comparisons were made at the p<0.05 level of significance. The result show that the age of drowning accidents for victims aged 20-29 was 27.9%, and for victims aged 30-39 years, 18.7%. In reguard to the age group, drowning accidents during recreational aquatic activity was age 20-39; 51(44.8%). In reguard to the locations, the number of drowning accidents in a lake or reservoir during recreational aquatic activity was 62(53.4%). The number of drowning accidents in a lake or reservoir during etc was 51(58%). In reguard to the days, the number of drowning accidents on Saturday during recreational aquatic activity was 30(25.8%), on Sunday 32(27.6%). The weather of drowning accidents during recreational aquatic activity was sunny 60(51.8%), rainy 40(34.4%), cloudy 16(13.8%). The season of drowning accidents during recreational aquatic activity was summer 53(45.7%). In reguard to season, two groups are significantly different. Drowning is a leading cause of injury related accidents. Understanding the characteristics of drowning is the first step to developing prevention strategies that may be beneficial for people of all ages and under nearly all circumstances are increased swimming ability, lifeguard staffing, providing life jackets, and public education activities.

• Journal of the Korean Geosynthetics Society
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• v.20 no.2
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• pp.23-33
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• 2021

In Korea, many reservoirs have been built for the purpose of solving the food shortage problem and supplying agricultural water. However, the current 75.6% of the reservoirs are in serious aged as more than 50 years have passed since the year of construction. In the case of such an aging reservoir, the stability due to scour and erosion inside the reservoir is very reduced, and if concentrated rainfall due to recent abnormal weather occurs, the aging reservoir may collapse, leading to a lot of damage to property and human life. Accordingly, each agency that manages aging reservoirs uses Ordinary Portland Cement (OPC) as an injection material and applies the grouting method. However, in the case of OPC, it may deteriorate over time and water leakage may occur again. And there are environmental problems such as consumption of natural resources and generation of greenhouse gases. So, there is a need to develop new materials and methods that can replace the OPC. In this study, an laboratory test and analysis were performed on the grout material developed to induce a curing reaction similar to that of OPC by recycling power plant byproduct. In addition, test in the field such as electric resistivity survey, Standard Penetration Test (SPT), and field permeability test were performed to analyzed to reinforcement effect and determine the possibility of using instead of OPC. As a results of the test, in the case of recycled power plant byproduct, the compressive strength was 2.9 to 3.2 times and the deformation modulus was 2.3 to 3.3 times higher, indicating that it is excellent in strength and can be used instead of OPC. And it was analyzed that the N value of the reservoir was increased by 1~2, and the coefficient of permeability (k) decreased to the level of 8.9~42.5%. showing sufficient reinforcing effect in terms of order.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.1-9
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• 2020

Acritical function of a nation is to protect its people's lives and properties from natural disasters such as a drought. A drought affects many aspects of human life, including social, economic, and industrial activities. Approximately 75.7% of reservoirs in Korea are over 50 years old.Sedimentation over the years may have caused a situation where storage capacity of the reservoirs is no longer sufficient and compliant with the original reservoir specifications. This study analyzes storage capacities for ten aged reservoirs using the autonomous navigation USV. It compares these capacities with sediment estimated by conventional empirical equations. Comparisons were made to the original specifications for the reservoirs.Storage capacity of six reservoirs decreased in a range between 16.2%-55.3% and storage capacity of 4 reservoirs increased in a range between 1.5%-380.2%. This data was compared to data derived from estimating sediment by empirical equations. Yoon's equation(1982) appeared more accurate than Sur's equation(1988) in Uhlinzi and Yongpo reservoirs, and Sur's equation(1988), however, appeared more accurate than Yoon's equation in Daegok, Ugok2 and Ochi reservoirs. The significant ranges of sedimentation shown in this study suggest that it is worth continuously surveying reservoirs to ensure their efficient management and operation.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.4
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• pp.413-428
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• 2013

In this study, Ant Colony Algorithm(ACO) was used for optimal model. ACO which are metaheuristic algorithm for combinatorial optimization problem are inspired by the fact that ants are able to find the shortest route between their nest and food source. For applying the model to water distribution systems, pipes, tanks(reservoirs), pump construction and pump operation cost were considered as object function and pressure at each node and reservoir level were considered as constraints. Modified model from Ostfeld and Tubaltzev(2008) was verified by applying 2-Looped, Hanoi and Ostfeld's networks. And sensitivity analysis about ant number, number of ants in a best group and pheromone decrease rate was accomplished. After the verification, it was applied to real water network from S water treatment plant. As a result of the analysis, in the Two-looped network, the best design cost was found to $419,000 and in the Hanoi network, the best design cost was calculated to $6,164,384, and in the Ostfeld's network, the best design cost was found to $3,525,096. These are almost equal or better result compared with previous researches. Last, the cost of optimal design for real network, was found for 66 billion dollar that is 8.8 % lower than before. In addition, optimal diameter for aged pipes was found in this study and the 5 of 8 aged pipes were changed the diameter. Through this result, pipe construction cost reduction was found to 11 percent lower than before. And to conclusion, The least cost design model on water distribution system was developed and verified successfully in this study and it will be very useful not only optimal pipe change plan but optimization plan for whole water distribution system.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.2
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• pp.53-62
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• 2020

The purpose of this study is to estimate the channel water loss of agricultural water supply in the command areas belong to Yechon irrigation channel of Gyeongcheon reservoir located Mungyeong-si, which area experienced a severe drought in 2015. The channel water loss was estimated by comparison of the irrigation water requirements (IWR) and agricultural water supply of the field data from 2012 to 2015. Further analysis was conducted to define the conveyance loss estimated based on the leakage holes and illegal pumping spots investigated through the field survey, and the distribution loss obtained by subtracting conveyance loss from the channel water loss. The annual rainfall decreased gradually, but the contribution of effective rainfall, available rain water to crop, increased to IWR during the study period. These phenomena resulted in the increase of agricultural water supply, and hence made greater the channel water loss simultaneously. The average channel water losses estimated as 36.8 % with 7.1 % of the conveyance loss and 29.7 % of distribution loss respectively. The distribution loss seems to be related to total number of rainy days, and irrigation schedules, while the conveyance loss was caused by irrigation channel aging conditions and illegal intake problems. In order to achieve sustainable agricultural water resources, the channel water loss needs to be reduced through the restoration of aged irrigation facilities and effective water managements in the fields.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.101-115
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• 1991

A study on the method of evaluation the urban amenity structure in Pusan city was established. Finally a survey sites out of 41 regions were selected on the basis of questionnaires : Taejong-dae and Haeun-dae as a seascape, Pumosa and Daesin-park as a mountain, Daechong-park and Seongjigok-park as a mixed, and Chungryulsa, Yongdoosan-park and U. N. Cemetry as a urban type. The abstracted results of amenity elements were revealed as natural environments including convex type as beach, reservoir, valley and mountain, and plant elements including woods and flower beds which raised amenity. The elements of social surroundings including children's playing, the aged's rest, and elements of structures including historic and memorial structures and high buildings. Amenity element made up of each space by region were abstracted from the Semantic Differential method. According to the factor analysis on the ground SD scale values, Kaiser's measure of sampling adequacy for 24 variables is 08602 and very high. Four factors including pleasantness, healthiness, convenience and safety showed 54.42 percent for total variance. By means of multiple regression, the model was as follows : Y=1.6636+0.3684X4+0.1955X11+0.1614X15-0.1688X23+0.1468X24. Therefore, Y:amenity, X4:beautiful-ugly, X11:clean-dirty, X15:creative-imitative, X23:cozy-dreary, X24:free-restrained. All variables in the model were significant at 0.001 level. According to the results of regression on satisfaction, the variables of satisfaction affecting amenity are the size of green space, the condition of management and the harmony with the surroundings. I think the considerating on the above could improve amenity of each region and further Pusan city.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.278-282
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• 2004

Compost is used mainly as an organic fertilizer, but it is also used as bedding material for cattle. Dairy cattle have been identified as a main reservoir of pathogenic Escherichia coli O157:H7. Further, E. coli is regarded as an environmental pathogen that causes bovine clinical mastitis. Hence, its growth in compost spread or compost bedding should be avoided. Physical and chemical conditions, available nutrients and microflora in compost change greatly during the composting process. Since pathogen growth in compost seems to be related to these changes, we assessed the possibility of E. coli growth in compost samples collected at 0, 7, 13, 22, 41, 190 and 360 d. Cattle waste composts with and without added tofu residue were collected from static piles and immediately air-dried. Compost samples were inoculated with a pure culture of E. coli, the moisture content was adjusted to 50%, and the samples were incubated for 5 d at $30^{\circ}C$. The numbers of E. coli in compost before and after incubation were determined by direct plating on Chromocult coliform agar. Almost all compost samples supported E. coli growth. Samples collected during or immediately after the thermophilic phase (day 7) showed the highest growth. Growth in samples more than 13 d old were not significantly different from those of aged compost samples. The addition of tofu residue gave a higher growth than its absence in younger samples collected prior to 13 d. To minimize the risk of environmental mastitis, the use of compost in the initial stage of the process is better avoided.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1755-1760
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• 2013

Objective: To investigate the prevalence of genital high-risk human papillomavirus (HR-HPV) in male sexual partners of HR-HPV infected women and the concordance of viral types in couples in China, and comprehend the role of men play in HPV transmission to women. Methods/Materials: 94 asymptomatic women and their husbands from rural Chaozhou participated in epidemiologic screening for HPV infection. Cervical cells from females were collected for high risk HPV screening by real time-PCR, and they were positive for at least 1 of 13 HR-HPV subtypes, then these samples were genotyped. Approximately one mouth later, penile epithelial cells from 94 asymptomatic husbands were collected for HPV genotyping. At the same time, a cross-sectional study was conducted in 366 male patients from sexually transmitted disease (STD) outpatient clinic in China for the prevalence of genital HR-HPV infection in men having frequent sex behavior. Penial epithelial cells were collected for HPV 6/11 and HPV 16/18 detection by fluorescent real-time quantified PCR. Results: Among 94 couples, the prevalence of genital HR-HPV infection in men whose wife was positive for cervical HR-HPV was 5.32% (5/94). Only 2.63% (2/76) had the same high risk viral type presented by their wife. HPV 16 proved to be the most prevalent viral type in men and in couples. Of 366 male patients from STD outpatient clinic, the prevalence of HPV 16/18 infection in men with or without HPV 6/11 was 6.85% and 8.16%, respectively. The incidence of HPV 16/18 was higher in men aged more than 35 years than the young men (18-35 years). Conclusion: The prevalence of genital HR-HPV infection in male sexual partners of HPV-positive women in China was lower than that expected, and the concordance of high risk viral type between couples was extremely low. These data suggested that infected men consitute an important viral reservoir, contributing to transmission of HR-HPV to women and maintenance of infection, but HR-HPV infection may be less likely to persist in men than in women.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.159-166
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• 2003

The purpose of this study was to investigate and compare the frequence of 4 periodontal pathogens in the supra- and subgingival plaque in periodontally healthy subjects. Twenty adult individuals aged 22 to 28 years (mean age 23.65 years) participated in this study. All subjects had no pocket sites more than 3 mm deep, and the sites selected for sampling were all negative for bleeding. After drying and isolation of the sites with cotton rolls, supragingival plaque was sampled using sterile periodontal curette. Each plaque sample was placed in individual tubes containing 500 ml of 1X PBS. After removal of the supragingival sample and any remaining supragingival plaque, subgingival plaque samples were taken from the same sites using sterile curette and placed in similar individual tubes. Identification of 4 putative periodontal pathogens from the samples was performed by polymerase chain reaction based on 16S rDNA. Chi-square test was employed to identify significant explanatory variables for the presence of the 4 periodontal pathogens. The data show that Actinobacillus actinmycetemcomitans, Porphyromonanas gingivalis, Bacteroides forsythus, and Fusobacterium nucleatum occurred in 16.9%, 14.4%, 52.5%, and 80.6%, respectively. No significant differences were noted in the periodontal pathogens between supra- and subgingival plaques according to the kind of teeth. However, the incisors were at higher risk for harboring F. nucleatum (p <0.05). Conclusion: These results reveal that anaerobic periodontal pathogens can be detected in supragingival plaques. Supragingival plaque may function as a reservoir of peri-odotopathogens.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.42-55
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• 2011

The basic approach of this study was to take the theory of cultural fluctuations to investigate the early modern and modern patterns of the use of ox carts and@ the social and economic appropriateness and cultural significance of ox carts. The study chose a village that was the only place that used ox carts in Bugye-myeon. The findings will help to understand how traditional cultural elements would continue or change according to the natural, geographical, economical, and cultural characteristics of a village. Located in Gaho-2-ri, Bugye-myeon, Gunwi-gun, Gyeongbuk Province, Dongrim Village started to use ox carts during the Japanese rule and replaced the traditional version with an improved one in 1972 when a reservoir was built. Until the 1970s, they used ox carts to carry agricultural products and luggage and to visit the markets in distant Bugye-myeon or Gunwi-eup. In the early 1980s when a cultivator was first introduced into the village, ox carts gradually disappeared in the village and eventually remained as a mere means of transportation. As the younger generations were active in introducing modern means of transportation, a cultivator became the main means of transportation in the village in the 1980s and a truck since the latter half of the 1990s. Despite those changes, however, the elderly in their seventies or older continued to use ox carts. With aged labor and inability to use modern means of transportation, they grew cows and oxen to cultivate the inclined fields and gain easy access to fields distributed in distant locations and continued to ox carts through reform. In Dongrim Village, the heritage of using reformed ox carts is the practice of appropriate technology by the old farmers and a cultural representation of an aged agricultural society. That is, the elderly recognized the appropriateness and practicality of traditional culture and renewed a traditional means of transportation called an ox cart. The phenomenon of the old men and women frequently using ox carts in an agricultural village in the mountain with geographical limitations has settled down as a cultural representation of the elderly in Dongrim Village. The continuing usage of ox carts in Dongrim Village is attributed to the fact that ox carts well suit the natural, geographical, and economic aspects of the village and the cultural inertia of the elderly with the aging of the farmers. Thus it is once again shown that human beings transmit and alter culture according to their overall situations and conditions.