• Journal of Environmental Science International
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• v.26 no.1
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• pp.47-54
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• 2017

We analyzed the variation in occurrence time and intensity of attacks by the rice stem borer (Chilo suppressalis Walker) on several crops. This study aimed to understand how C. suppressalis damages crops and to utilize this basic data for the establishment of environment-friendly control methods like pheromone traps. This study surveyed the changes in occurrence patterns of C. suppressalis, biological characteristics of overwintering larvae, and the efficacy of different types of pheromone traps the years. We found similar occurrence patterns of C. suppressalis in different crops. In addition, occurrence time of the first generation was advanced. Overwintering larvae showed no difference in pupal period and weight compared to the non-overwintering ones. However, the larval period was reduced to 19.1 days in Miscanthus field, in contrast to that in the paddy fields. It was confirmed that larvae of C. suppressalis generally prefer the lower part of the stems of Miscanthus. Efficiency of the emergence trap was confirmed to be greater than that of the delta trap for capturing C. suppressalis adults. However, it is necessary to adjust the control period because of the advancement in occurring time of C. suppressalis in recent years. The larvae of C. suppressalis experience favorable environmental conditions for overwintering in Miscanthus fields. The major Miscanthus fields are generally located in the areas protected for sources of drinking water, owing to which spraying of chemical pesticides is very limited. The results of this study provide important inputs for the development of environment-friendly control methods.

• Journal of Preventive Medicine and Public Health
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• v.38 no.4
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• pp.391-400
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• 2005

Objective : This study examined the socioeconomic differentials for the health and health related behaviors among South Korean middle school students. Methods : A nationwide cross-sectional interview survey of 3,449 middle school second-grade students and their parents was conducted using a stratified multi-stage cluster sampling method. The response rate was 93.3%. The socioeconomic position indicators were based on self-reported information from the students and their parents: parental education, father's occupational class, monthly family income, out-of-pocket expenditure for education, housing ownership, educational expectations, educational performance and the perceived economic hardships. The outcome variables that were measured were also based on the self-reported information from the students. The health measures included self-rated health conditions, psychological or mental problems, the feelings of loneliness at school, the overall satisfaction of life and the perceived level of stress. The health related behaviors included were smoking, alcohol drinking, sexual intercourse, violence, bullying and verbal and physical abuse by parents. Results : Socioeconomic differences for the health and health related behaviors were found among the eighth grade boys and girls of South Korea. However, the pattern varied with gender, the socioeconomic position indicators and the outcome measures. The prevalence rates of the overall dissatisfaction with life for both genders differed according to most of the eight socioeconomic position indicators. All the health measures were significantly different according to the perceived economic hardship. However, the socioeconomic differences in the self-rated health conditions and the psychosocial or mental problems were not clear. The students having higher socioeconomic position tended to be a perpetrator of bullying while those students with lower socioeconomic position were more likely to be a victim. Conclusions : The perceived economic hardships predicted the health status among the eighth graders of South Korea. The overall satisfaction of life was associated with the socioeconomic position indicators. Further research efforts are needed to explore the mechanisms on how and why the socioeconomic position affects the health and health related behaviors in this age group.

• Journal of Preventive Medicine and Public Health
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• v.26 no.3 s.43
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• pp.332-346
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• 1993

This study was attempted to observe leisure time physical activity pattern and its relationship to coronary risk factors (BMI, systolic blood pressure, diastolic blood pressure, serum total cholesterol, triglycerides, fasting blood sugar). Subjects participated in this study were 277 adult male workers of an industry in Kyungpook province, Korea. Energy expenditure were measured using modified Physical Activity History questionnaire of CARDIA study by interviewing. Serum total cholesterol, triglycerides and blood sugar level were tested with 5 ml fasting blood and height, weight and blood pressure were masured. Data on smoking and drinking habits and others were obtained. Geometric mean of leisure time physical energy expenditure were estimated as 212.80 kcal per week for study subjects and only 22.4% of them expended 2,000 kcal or more per week in leisure time physical activity. Taking walks or hikes and jogging or running were more frequent leisure time physical activities in study subjects. Statistically significant mean differences in total weekly leisure time physical activity for all coronary risk factors were not found among three groups. Because energy expenditure of leisure time was generally low in this subjects and most of them were healthy men, we did not found that leisure time physical activity was significantly associated with coronary risk factors.

• Korean Journal of Ecology and Environment
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• v.43 no.4
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• pp.492-502
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• 2010

The study objects were to analyze long-term and seasonal variations of nutrients (N, P), suspended solids, N:P ratios, algal chlorophyll, and trophic state along with general water quality parameters in four sampling sites including two intake tower sites supplying drinking water in Daechung Reservoir. For the analysis, we used water quality long-term data sampled during 1998~2007 by the Ministry of Environment, Korea. Interannual and seasonal trends in inflow and discharge near the intake tower facilities over the ten years were directly influenced by rainfall pattern. The distinct difference between wet year (2003) and dry year (2001) produced marked differences in water temperature, pH, dissolved oxygen, organic matter contents, nutrients, and these variables influenced algal biomass and trophic state. Values of TP varied depending on the year and locations sampled, but monthly mean TP always peaked during July~August when river inflow and precipitation were maxima. In contrast, TN varied little compared to TP, indicating lower influence by seasonal flow compared to phosphorus. The number of E. coli were highest in Site 2 (Chudong intake tower) and varied largely, whereas at other sites, the numbers were low and low variations. Contents of chlorophyll-${\alpha}$ (CHL), as an estimation of primary productivity, varied largely depending on the year and season. The maximum of CHL occurred at Muneu intake tower (S4) during 2006 when the precipitation and inflow were lowest. In contrast, another CHL peak was observed in Site 2 (Chudong intake tower) in 2006 when one of the largest typoons (Ewinia) occurred and river runoff were maximum. So the CHL maxima were associated with both wet year (high flow, high nutrient supply) and dry year (low flow, nutrient supply by littoral zone). Such conditions influenced trophic states, based on Trophic State Index of nutrients and CHL. Based on all analyses, we can provide some clues for management and protection strategies of two intake tower sites.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.1
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• pp.21-26
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• 2014

Objectives: The purpose of this article is to analyze the incidence, demographic distribution, type, and etiology of mandible fractures that were treated by the Department of Oral and Maxillofacial Surgery in Kyung Hee University Dental Hospital from January 2002 to December 2012. Materials and Methods: This was a descriptive and analytic retrospective study that evaluated 735 patients that were treated for mandible fracture. Results: This study included 1,172 fractures in 735 patients. The ratio of male to female patients was 5.45 : 1; the maximum value was in patients between 20 and 29 years (38.1%) and the minimum in patients over 70 years old. The monthly distribution of facial fractures peaked in the fall and was lower during winter. No specific correlation was identified based on the annual fracture distribution. Among the 735 fracture patients, 1.59 fracture lines were observed per patient. The most frequent site was the symphysis, which accounted for a total of 431 fractures, followed by the angle (348), condyle (279), and body (95). The symphysis with angle was the most common site identified in combination with fracture and accounted for 22.4%, followed by symphysis with condyle (19.8%). The angle was the most frequent site of single fractures (20.8%). The major cause of injury was accidental trauma (43.4%), which was followed by other causes such as violence (33.9%), sports-related accidents (10.5%), and traffic accidents (10.1%). Fracture incidents correlated with alcohol consumption were reported between 10.0%-26.9% annually. Conclusion: Although mandible fracture pattern is similar to the previous researches, there is some changes in the etiologic factors.

• Environmental Analysis Health and Toxicology
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• v.11 no.1_2
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• pp.19-29
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• 1996

Human exposure to volatile compounds in tap water can occur from inhalation and dermal absorption as well as direct ingestion. The relative contribution to total human exposure from these pathways has been considered to be important especially for VOC's (volatile organic compounds). In an attempt to reduce the uncertainty of the risk assessment, it has been suggested that the exposure assessment process could be significantly improved by adopting Monte-Carlo simulation. However, there is no actual data in Korea for each exposure parameter to determine the level of exposure, and the distributional pattern. Therefore, we surveyed water use patterns and behavior related to multi-route exposure to VOC's in household tap water in Korea, and compared these values to the those in western countries. In the first survey, we calculated daily water intake using data from a sample of 1322 persons of several cities in Korea. In the second survey, we obtained questionnaire data on exposure time for showering, bathing and household activities, and tap water intake from 851households in Korea. In the last survey, we measured the exposure parameters (exposure time, water use rate etc.) related to showers, baths, toilets, dish washing, washing and cooking, and tap water intake was surveyed. Also, the subjects were measured their body weight, height and tidal volume, etc. A diary, a flow meter and a measuring cup were used to measure these values as precisely as possible. Average daily water intake was ranged 0.79-1.71 L/day for adults in three surveys. Tap water intake measured by log-sheet during one week in third survey was 1.26 (average), 1.98 L/day (90 percentlie), respectively. These results were comparable with results from EPA (1.4, 2L/day). The average amount of water used by housewives in the third survey was 515.0 $\pm$ 564.6L/day. In usual activity, the amount of water used in the bathroom, the laundry and the kitchen was 140.0 $\pm$ 538.9, 148.0 $\pm$ 174.5, 229.3 $\pm$ 205.4 L/day, respectively. Exposure parameters such as water intake rate, exposure duration, body weight, inhalation rates in surveyed data of Korean people differed from those published from western countries. This could be attributed to variations in lifestyle, dietary habits and physiological characteristics.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.3
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• pp.23-35
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• 2012

The optimum location of the prehistoric sites of Ulsan Metropolitan City are investigated by both quantile and natural breaks methods through GIS, and the settlement pattern is studied based on the possibility of presence of the prehistoric sites which are also analyzed with these methods. Such factors including elevation, slope, distance from the nearest water, aspect, geological features, soil drainage classes, subsoil and land use recommended are employed in the analysis. The optimum geographical environment is the place where it includes the water-base in the area that is the southern aspect of the gentle slope land of lowland. The geology is the Quaternary alluvium. The drainage class is fine and the deep soil saturn is the fine loamy soil and the recommendation of land use is the area that is the field. As a result of the forecast of distribution, the prehistoric sites showed the higher possibility of presence in the downstream region where the Taehwa river and Dongcheon river join because the region come close to the watercourse and the drinking water use is easy. And the aspect and elevation is the low area. The alluvium accumulated from the upper stream of the Taehwa river and Dongheon river was made roomily, the area where is suitable for the farming life. Therefore, this region is judged that the possibility of presence of the prehistoric sites is high.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.411-418
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• 2004

Mercury, one of the most diffused and hazardous organ-specific environmental contaminants, exists in a wide variety of physical and chemical states. The murcury with the nature which evaporates easily can cause an acute or chronic mercury poisoning to workers at mercury-handling workplaces. Although many studies indicate that mercury induces a deleterious damage, little has been reported from the investigations of mercury effects at surrounding levels in living things. The purpose of this study was to evaluate the biological effects of mercury chloride and ionizing radiation. Prepubertal male F344 rats were administered mercury chloride in drinking water throughout the experimental period or were given wholebody irradiation with a dose of 6.5 Gy. The amount changed of body weight during the experimental period showed a 4.9% rise in the mercury-treated group and 14.4% decline in the irradiated group compared with the level of the control group. The results of hematological analysis (red blood cells, white blood cells, hemoglobin, and hematocrit) indicated the differential effects of mercury chloride and ionizing radiation. However the concentration of cortisol as assessed by radioimmunoassay increased in both of the groups. Relative expressions of mRNA related to mitochondrion-mediated apoptosis were investigated using semiquantitative reverse transcription polymerase chain reaction on gonad and urinary organs of the experimental groups. While the expression of Bcl-2 mRNA exhibited different patterns depending on the organs or the experimental groups, both of the experimental groups showed a conspicuous expressions of Bax mRNA. In conclusion, the target organ of mercury chloride seems to be a urinary organ and the pattern of damage induced by mercury chloride differs from that by ionizing radiation.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.281-293
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• 2018

Wetlands of Dongbaekdongsan were classified into two types of pond and vernal pool. 11 plant communities are established there such as Nymphoides indica community, Sparganium stoloniferum Community, Persicaria hastato-auriculata community, Scirpus triangulatus community, Triadenum japonica community, Juncus papillosus community, Deinostema violacea community, Centipeda minima community, Apocynum sibiricum community, Isachne globosa community, and Ulmus parvifolia community. Nymphoides indica community is established in a pond located on the entrance of the Dongbaekdongsan and Persicaria hastatoauriculata community appears on edge of the pond. Sparganium stoloniferum community is formed in nearby pond with relatively shallow water and Persicaria hastatoauriculata community is established on margin of the pond. Vernal pools had been used for drinking water source and for livestock in some cases in the past. Scirpus triangulatus community is established in the most wet site as the center of the pools and Juncus papillosus community - Deinostema violacea community - Triadenum japonica community, and Apocynum sibiricum community appear in a concentric circle pattern as far away there. Ulmus parvifolia community is established in a dry vernal pool. This is the first study on vernal pool carried out in Korea. Therefore, most vegetation types are new ones different from existing studies on wetland.

• The Journal of Korean Medical History
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• v.26 no.1
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• pp.87-96
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• 2013

This study confirmed that a doctor named Lee, Seok-gan whose name has been widely known but whose real identity has remained unclear, was an active Confucian doctor in the 16th century. In addition, through the newly discovered "Daeyakbu" among his family line, writings, and relics that have been handed down in a family, this study looked into his medical philosophy and medicine culture. The author of "Ieseokgangyeongheombang"(Medical Book by Lee, Seok-gan(李石澗), Seok-gan is the same person as an active famous doctor Lee, Seok-gan(李碩幹, 1509-1574) in the 16th century. Such a fact can be confirmed through "Samuiilheombang", "Sauigyeongheombang" and the newly opened "Ieseokgangyeongheombang". Lee, Seok-gan was born in the 4th ruling year of king Jungjong (1509) and was active as a doctor until the 7th ruling year of king Seonjo(1547); his first name is Jungim with the pen name-Chodang, and he used a doctor name of 'Seokgan.' He was known as a divine doctor, and there have been left lots of anecdotes in relation with Lee, Seok-gan. Legend has it that Seokgan went to China to give treatment to the empress, and a heavenly peach pattern drinking cup and a house, which the emperor bestowed on Seokgan in return for his great services, still have remained up to the present. Usually, Seokgan interacted with Toegye Lee Hwang and his literary persons, and with his excellent medical skills, Seokgan once gave treatment to Toegye at the time of his death free of charge. His medical skills have been handed down in his family, and his descendant Lee, Ui-tae(around 1700) compiled a medical book titled "Gyeongheombangwhipyeon(經驗方彙編)". Out of Lee, Seok-gan's keepsakes which were donated to Sosu museums by his descendant family, 4 sorts of 'Gwabu'(writings of fruit trees) including "Daeyakbu" were discovered. It's rare to find a literary work left by a medical figure like this, so these discoveries have a deep meaning even from a medicine culture level. Particularly, "Daeyakbu" includes the typical "Uigukron". The "Uigukron", which develops its story by contrasting politics with medicine, has a unique writing style as one of the representative explanatory methods of scholars' position during the Joseon Dynasty; in addition, the distinctive feature of "Uigukron" is that it was created in the form of 'Gabu' other than a prose.