• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.45-59
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• 1997

It has been known that there is a tracking phenomenon in the level of serum lipids. However, no study has been performed to examine the change and tracking of serum lipids in Korean adolescents. The purpose of this study is to examine the changes of serum lipids in Korean adolescents from 12 to 16 years of age, and to examine whether or not there is a tracking phenomenon in serum lipids level during the period. In 1992 serum lipids(total cholesterol(TC), triglyceride(TG), LDL cholesterol(LDL-C), HDL cholesterol(HDL-C)) were measured in 318 males, 365 females who were 12 years of age in Kangwha county, Korea. These participants have been followed up to 1996 and serum lipids level were examined in 1994 and 1996. Among the participants 162 males and 147 females completed all three examinations in fasting state. To examine the effect of eliminating adolescents with incomplete data, we compared serum lipids, blood pressure and anthropometric measures at baseline between adolescents with complete follow-up and adolescents who were withdrawn. To examine the change of serum lipids we compared mean values of serum lipids according to age in males and females. Repeated analysis of variance was used to test the change according to age. We used three methods to examine the existence of tracking. First, we analyzed the trends in serum lipids over 4-year period within quartile groups formed on the basis of the first-year serum lipids level to see whether or not the relative ranking of the mean serum lipids among the quartile groups remained in the same group for 4-year period. Second, we quantified the degree of tracking by calculating Spearman's rank correlation coefficient between every tests. Third, the persistence extreme quartile method was used. This method divides the population into quartile groups according to the initial level of blood lipids and then calculates the percent of the subjects who stayed in the same group at follow-up measurement. The decreases in levels were noted during 4 years for TC, LDL-C, primarily for boys. The level of HDL-C decreased between baseline and first follow-up for both sexes. Tracking, as measured by both correlation coefficients and persistence extreme quartiles, was evident for all of the lipids. The correlation coefficients of TC between baseline and 4 years later in boys and girls were 0.55 and 0.68, respectively. And the corresponding values for HDL-C were 0.58 and 0.69. More than 50% of adolescents who belonged to the highest quartile group in TC, HDL-C and LDL-C at the baseline were remained at the same group at the examination performed 2 years later for both sexes. The probabilities of remaining at the same group were more than 35% when examined 4 years later. The tracking phenomenon of TG was less evident compared with the other lipids. Percents of girls who stayed at the same group 2 years later and 4 years later were 42.9% and 25.7%, respectively. It was evident that serum lipid levels tracked in Korean adolescents. Researches with longer follow-up would be needed in the future to investigate the long-term change of lipids from adolescents to adults.

• Economic and Environmental Geology
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• v.48 no.2
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• pp.147-160
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• 2015

In 2014, on 31 August and 1 September, the emissions of $CH_4$, $CO_2$, and $O_2$ gases were measured six times using the closed chamber method from exposed tidal flat sediments in the same position relative to the low point of the tidal cycle in the Eoeun-ri, Taean-gun, on the Mid-western Coast of Korea. The concentrations of $CH_4$ in the air sample collected in the chamber were measured using gas chromatography with an EG analyzer, model GS-23, within 6 hours of collection, and the other gases were measured in real time using a multi-gas monitor. The gas emission fluxes (source (+), and sink (-)) were calculated from a simple linear regression analysis of the changes in the concentrations over time. In order to see the surrounding parameters (water content, temperature, total organic carbon, average mean size of sediments, and the temperature of the inner chamber) were measured at the study site. On the first day, across three measurements during 5 hours 20 minutes, the observed $CO_2$ flux absorption was -137.00 to $-81.73mg/m^2/hr$, and the $O_2$ absorption, measured simultaneously, was -0.03 to $0.00mg/m^2/hr$. On the second day using an identical number of measurements, the $CO_2$ absorption was -20.43 to $-2.11mg/m^2/hr$, and the $O_2$ absorption -0.18 to $-0.14mg/m^2/hr$. The $CH_4$ absorption before low tide was $-0.02mg/m^2/hr$ (first day, Pearson correlation coefficient using the SPSS statistical analysis is -0.555(n=5, p=0.332, pronounced negative linear relationship)), and $-0.15mg/m^2/hr$ (second day, -0.915(n=5, p=0.030, strong negative linear relationship)) on both measurement days. The emitted flux after low tide on both measurement days reached a minimum of $+0.00mg/m^2/hr$ (+0.713(n=5, p=0.176, linear relationship which can be almost ignored)), and a maximum of $+0.03mg/m^2/hr$ (+0.194(n=5, p=0.754, weak positive linear relationship)) after low tide. However, the absolute values of the $CH_4$ fluxes were analyzed at different times. These results suggest that rate for $CH_4$ fluxes, even the same time and area, were influenced by changes in the tidal cycle characteristics of surface sediments for understanding their correlation with these gas emissions, and surrounding parameters such as physiochemical sediments conditions.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.625-636
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• 2011

The purpose of this study was to evaluate the relationship between bone health and sodium intake in female university students using a dish frequency questionnaire (DFQ 125), anthropometric checkups, food records for 3 days, and ultrasound measurement of calcaneus bone mineral density. Subjects were divided into two groups: normal (n=196) and osteopenia (n=52). There were no significant differences in age or height between the two groups. The average weight, body mass index, and body fat in the normal group were significantly higher than in the osteopenia group. The sodium intake of DFQ was positively correlated with the sodium intake of 3 days of dietary records (p=0.0003). There were no significant differences in the sodium intake between the two groups from DFQ. The dishes were ranked by sodium intake: kimchies were 17.68%, noodles and mandu were 16.36%, stews were 13.69%, main dishes such as meat, egg, and beans were 11.47%, and fish and shellfish were 11.07%. The frequency of eating noodles and mandu (p=0.0116), stews (p=0.0008), kimchies (p=0.0482), fish and shellfish (p=0.0362), vegetables (p=0.0064) and seasoning (p=0.0347) were negatively associated with bone mineral density. Bone health was not significantly different with increasing quartiles of sodium intake. As excessive sodium intakes may indirectly affect bone mineral density, these results suggest that to prevent osteoporosis, university students needed to be more educated about diets containing less sodium through nutrition education programs.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.4
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• pp.292-302
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• 2012

This paper reviews comparison analysis of current and latest application for stock identification methods of Todarodes pacificus, and the pros and cons of each method and consideration of how to compensate for each other. Todarodes pacificus which migrates wide areas in western North Pacific is important fishery resource ecologically and commercially. Todarodes pacificus is also considered as 'biological indicator' of ocean environmental changes. And changes in its short and long term catch and distribution area occur along with environmental changes. For example, while the catch of pollack, a cold water fish, has dramatically decreased until today after the climate regime shift in 1987/1988, the catch of Todarodes pacificus has been dramatically increased. Regarding the decrease in pollack catch, overfishing and climate changes were considered as the main causes, but there has been no definite reason until today. One of the reasons why there is no definite answer is related with no proper analysis about ecological and environmental aspects based on stock identification. Subpopulation is a group sharing the same gene pool through sexual reproduction process within limited boundaries having similar ecological characteristics. Each individual with same stock might be affected by different environment in temporal and spatial during the process of spawning, recruitment and then reproduction. Thereby, accurate stock analysis about the species can play an efficient alternative to comply with effective resource management and rapid changes. Four main stock analysis were applied to Todarodes pacificus: Morphologic Method, Ecological Method, Tagging Method, Genetic Method. Ecological method is studies for analysis of differences in spawning grounds by analysing the individual ecological change, distribution, migration status, parasitic state of parasite, kinds of parasite and parasite infection rate etc. Currently the method has been studying lively can identify the group in the similar environment. However It is difficult to know to identify the same genetic group in each other. Tagging Method is direct method. It can analyse cohort's migration, distribution and location of spawning, but it is very difficult to recapture tagged squids and hard to tag juveniles. Genetic method, which is for useful fishery resource stock analysis has provided the basic information regarding resource management study. Genetic method for stock analysis is determined according to markers' sensitivity and need to select high multiform of genetic markers. For stock identification, isozyme multiform has been used for genetic markers. Recently there is increase in use of makers with high range variability among DNA sequencing like mitochondria, microsatellite. Even the current morphologic method, tagging method and ecological method played important rolls through finding Todarodes pacificus' life cycle, migration route and changes in spawning grounds, it is still difficult to analyze the stock of Todarodes pacificus as those are distributed in difference seas. Lately, by taking advantages of each stock analysis method, more complicated method is being applied. If based on such analysis and genetic method for improvement are played, there will be much advance in management system for the resource fluctuation of Todarodes pacificus.

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.180-190
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• 2000

Background: Genomic instability, which is manifested by the replication error(RER) phenotype, has been proposed for the promotion of genetic alterations necessary for carcinogenesis. Merlo et al. reported frequent microsatellite instability in primary small cell lung cancers. However, Kim et al. found that instability occurred in only 1% of the loci tested and did not resemble the replication error-positive phenotype. The significance of microsatellite instability in the tumorigenesis of small cell lung cancer as well as the relationship between microsatellite instability and its clinical prognosis was investigated in our study. Methods: Fifteen primary small cell lung cancers were chosen for this study. The DNAs extracted from paraffin-embedded tissue blocks with primary tumor and corresponding control tissue were investigated. Forty microsatellite markers on chromosome 1p, 2p, 3p, 5q, 6p, 6q, 9p, 9q, 13q, and 17p were used in the microsatellite analysis. Results: Thirteen(86.7%) of 15 tumors exhibited LOH in at least one of the tested microsatellite markers. Three of 13 tumors exhibiting LOH lost a larger area in chromosome 9p. LOH was shown in 72.7% on chromosome 2p, 40% on 3p, 50% on 5q, 46.7% on 9p, 69.2% on 13q, and 66.7% on 17p(Table 1). Nine(60%) of 15 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Nine cases exhibiting shifted bands showed altered loci ranging 2.5~52.5%(mean $9.4%\pm16.19$)(Table 2). Shifted bands occurred in 5.7% (34 of 600) of the loci tested(Table 2). Nine cases with shifted bands exhibited LOH ranging between 0~83.3%, and the median survival duration of those cases was 35 weeks. Six cases without shifted bands exhibited LOH ranging between 0~83.3%, and the median survival duration of those cases was 73 weeks. There was no significant difference between median survival durations of the two groups(p=0.4712). Conclusion: Microsatellite instability as well as the inactivation of several tumor suppressor genes may play important roles in the development and progression process of tumors. However, the relationship between microsatellite instability and its clinical prognosis in primary small cell lung cancer could not be established.

• Journal of Technologic Dentistry
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• v.17 no.1
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• pp.41-57
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• 1995

This study was conducted to collect and analyze previous information in order to manage efficience, improve experience effect and promote employment rate. The questionnaire interview with 27 chief of dental Laboratory refered clinical experience in technology department about clinical experience in 14 Jumior colleges were also investigated. The results were summarried as follows : The portion of age of 35-39 among chief of dental Laboratory was 40.7% which was the highest, that of male was 96.3%, that of junior college graduate was 97.5%, that of 10years experience was 92.6% and that of ceramic technician was 85.2%, 63.0% dental laboratory for clinical experience was a bore space of 30pyong. Aspect of dental laboratory management, manufacturing all part of prosthetic restoration was 29.6%, othodontic appliance and ceramic restoration was 7.4%, 3.8%, each. The percentage of 40.7 was having connection with 30-3a dental clinics and referring case per day was 10-19 cases(40.7%), manufacturing time of referred prosthetic restoration was 3-4 days(77.8%), places preparing seminar room for education was 29.6%, above a place of 40pyong was 11.1% 30-34 pyong and 35-39 pyong was 7.4% each. During training of 2 years education course student, 18.5% was rack of thorough occupational career. While 44.4% will want the more salary among 3years education course student, 74.1% will expect the more dental techmicians would engaged in their field, 51.9% will hope improve of their theory and practice, 29.6% be expected better skill and 14.8% be expected better theory. Attitude of clinical experience places was distributed by 59.3% of offering only experience chance, 25.9% of wasting time and 29.0% of annoying. The big emphasis of climical experience was thorough occupational career(44.4%). The clinical experience places of our college were selected after direct visiting, so their condition of management was not that bad but most of dental laboratory were poor in management state and working environment. Therefore it is difficult to choose appropriate places and dental Laboratory are also limited manpower and time as suppliers. So that it recommended to induce flexible management of experience period by interval and rotation of experience places among college and to applicate intern-system for employment ant industry-college cooperation aspect.

• KDI Journal of Economic Policy
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• v.13 no.1
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• pp.3-33
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• 1991

Since the early 1980's, the Korean government has gradually been widening the Korean market to foreign consumer goods. This, combined with the increased purchasing power of the Korean consumers resulting from the continued economic growth of the country, has sparked a spectacular influx of foreign consumer goods into Korea, ranging from BMW's to chopsticks. Import of foreign consumer goods amounted to more than 6 billion dollars in 1989 and is continuing to grow at a rapid rate. The increased import of foreign consumer goods doubtlessly improved the overall welfare of the Korean consumers by providing them with a wider range of options to choose from, by lowering the prices of some of the consumer goods domestically produced, and also by forcing the producers of some Korean goods to face competition with better foreign goods, thus giving them an incentive to raise the quality of their products. However, it is agreed by most economists that this increase in general welfare has been much smaller than what they had expected at the outset. Consumer prices of most imported consumer goods are easily double the import price, and in some cases, more than treble the import prices. Further, there has not been a noticeable drop in the prices of domestically produced consumer goods. Much of the blame has been attributed to the distribution sector of Korea. The objective of this paper is to analyze the imported consumer goods distribution sector of Korea, focusing on the possible sources of the poor performance of that sector, and to make policy suggestions that could potentially increase the welfare. This paper differs from all the previous research by others on this subject in that it analyzes the imported consumer goods distribution sector of Korea as a vertical structure. The distribution sector of an imported consumer good is a vertical structure since it consists of an international market, an import stage, and domestic wholesale and retail markets, in that order vertically. Our study naturally includes the analysis of the vertical restraints as well as the analysis of the industrial organization of each horizontal stage in the vertical structure. Each horizontal component of the imported consumer goods distribution sector is basically a monopolistically competitive market differentiated by characteristics of goods and by the locations and the services of firms. Further, restrictive dealership and resale price maintenance are found to be widely in use. Our main findings are the follwing; First, most consumer goods are imported monopolistically or oligopolistically through restrictive dealership contracts between foreign producers and domestic importers. Such restrictive dealership gives importers market power in the domestic market and explains many of the large discrepancies betwen the consumer prices and the import prices of many goods. Korean anti - trust law does not cover the issues arising from the market power of an importer resulting from a restrictive dealership contract. Second, some major producers of Korean goods are also importers of foreign goods that are substitutes of their products. The import of substitutes by major domestic producers is anti - competitive because it tends to raise the prices of both domestic goods and foreign goods, and also because it reduces the incentive of the domestic producers to raise the quality of their products. Third, wholesalers and retailers widely use resale price maintenance as a price fixing mechanism, and while this is against the anti- trust law, it seldom gets noticed. Fourth, the high level of rents of real estate for commercial use works as an entry barrier to the distribution sector and results in reduced competition by the firms in that sector. Finally, there are information problems. Consumers have inferior information to firms about the quality of a foreign consumer good that they have not tried before. Such information asymmetry often enables firms to raise prices. In addition, information asymmetry between importers frequently delays the import of cheaper substitutes. In order to alleviate the problems indentified above, we suggest the following policy changes. The government should strengthen the anti - trust law and its enforcement to regulate restrictive import contracts, import of competing goods by major domestic producers, and RPM by wholesalers and retailers that is aimed at price fixing. In addition, the government should loosen its tight real estate policy to encourage investment in the distribution sector. Finally, we suggest that the import price revelation policy that has been in use for some items since 1990 be expanded to most imported consumer goods that are introduced for the first time to give consumer better information and be used only for the period of time needed to inform sufficient number of consumers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.746-756
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• 2016

The purpose of this study was to investigate food safety knowledge, food safety attitudes, and handling behavior in the elderly. The survey was conducted on 358 individuals over 65 years old in urban and rural areas. Data were analyzed with descriptive analysis and ${\chi}^2$ test analysis of variance using SPSS. From the results on elderly's food safety knowledge, the item 'tangerines should be washed before eating' was correctly answered by urban subjects (75.4%) than rural subjects (49.7%). 'Is it okay to cook meat left on the sink since afternoon in the evening' showed the lowest correct answer rate in both urban (23.1%) and rural (31.9%) subjects. For the item related to food keeping, 'Bacterial cells do not multiply in Samgyetang when it is kept in a refrigerator right after boiling thoroughly', 58.5% of urban and 54.6% of rural elderly answered correctly. Most elderly people showed a tendency to think that boiled foods might be safe to eat. Secondly, for food safety attitudes, urban elderly had more proper attitude regarding the item, 'Namul is very tasty only when mixed with bare hands' (disagree rate 34.9%) than rural elderly (P<0.05)'. On the other hand, rural elderly had more positive attitudes regarding the store principle "first in, first out" compared to urban elderly (P<0.001). Thirdly, regarding food safety behaviors, only 67.9% of urban and 58.7% of rural elderly responded that they washed their hands right after answering the telephone while cooking. Exactly 33.8% of urban and 39.6% of rural older people replied 'defrost meat on top of sink or table' as the defrost method for frozen foods, showing that elderly did not recognize the risk of foodborne illness during improper defrosting at room temperature.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.465-478
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• 1995

The objective of this study was to investigate the impacts of large-scale timber harvesting on the environment of a mature hardwood forest. To achieve the objective, the effects of harvesting on forest environmental factors were analyzed quantitatively using the field data measured in the study sites of Seoul National University Research Forests [(Mt.) Paekunsan] for two years(1993-1994) following timber harvesting. The field data include information on vegetation, soil mesofauna, physicochemical characteristics of soil, surface water runoff, water quality in the stream, and hillslope erosion. For comparison, field data for each environmental factor were collected in forest areas disturbed by logging and undisturbed, separately. The results of this study were as follows : The diversity of vegetational species increased in the harvested sites. However, the similarity index value of species between harvested and non-harvested sites was close to each other. Soil bulk density and soil hardness were increased after timber harvesting, respectively. The level of organic matter, total-N, avail $P_2O_5$, CEC($K^+$, $Na^+$, $Ca^{{+}{+}}$, $Mg^{{+}{+}}$) in the harvested area were found decreased. While the population of Colembola spp., and Acari spp. among soil mesofauna in harvested sites increased by two to seven times compared to those of non-harvested sites during the first year, the rates of increment decreased in the second year. However, those members of soil mesofauna in harvested sites were still higher than those of non-harvested sites in the second year. The results of statistical analysis using the stepwise regression method indicated that the diversity of soil mesofauna were significantly affected by soil moisture, soil bulk density, $Mg^{{+}{+}}$, CEC, and soil temperature at soil depth of 5(0~10)cm in the order of importance. The amount of surface water runoff on harvested sites was larger than that of non-harvested sites by 28% in the first year and 24.5% in the second year after timber harvesting. The level of BOD, COD, and pH in the stream water on the harvested sites reached at the level of the domestic use for drinking in the first and second year after timber harvesting. Such heavy metals as Cd, Pb, Cu, and organic P were not found. Moreover, the level of eight factors of domestic use for drinking water designated by the Ministry of Health and Welfare of Korea were within the level of the first class in the quality of drinking water standard. The study also showed that the amount of hillslope erosion in harvested sites was 4.77 ton/ha/yr in the first year after timber harvesting. In the second year, the amount decreased rapidly to 1.0 ton/ha/yr. The impact of logging on hillslope erosion in the harvested sites was larger than that in non-harvested sites by seven times in the first year and two times in the second year. The above results indicate that the large-scale timber harvesting cause significant changes in the environmental factors. However, the results are based on only two-year field observation. We should take more field observation and analyses to increase understandings on the impacts of timber harvesting on environmental changes. With the understandings, we might be able to improve the technology of timber harvesting operations to reduce the environmental impacts of large-scale timber harvesting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1589-1598
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• 2008

The objective of this study was to investigate the effect of obesity on health by analyzing the factors which are related to obesity through the questionnaires on the dietary pattern, nutrient intake and physical measurements. The subjects, 419 college women aged 20 to 24 year-old, were randomly selected from Seoul and data were collected during March to May, 2008 and classified as under underweight, normal weight, and obesity groups according to BMI. However, weight, skeletal muscle mass, body fat mass, fat free mass, percentage of body fat, and waist to hip ratio showed significant differences among all the groups (p<0.05). In the obese group, 77.8% ate fat-rich foods such as galbi and samgyopsal more than two times per week, 66.7% ate vegetables other than kimchi (p<0.05) as compared to the underweight and normal groups by mini dietary assessment (p<0.05). The cholesterol intakes of the underweight, normal weight, and obese groups were $164.67{\pm}114.52mg/dL$, $143.31{\pm}99.58mg/dL$, and $121.92{\pm}54.91mg/dL$, respectively, and the obese group had a significantly lower intake than the other groups (p<0.05). The serum total cholesterol levels of the underweight, normal, and obese groups were $177.04{\pm}26.36mg/dL$, $189.46{\pm}29.05mg/dL$, and $170.00{\pm}12.75mg/dL$, respectively, and the obese group showed lower total cholesterol level than the other groups (p<0.05). The triacylglycerol level of the obese group ($132.00{\pm}64.60mg/dL$) was significantly higher than the other two groups (p<0.05). The HDL-cholesterol levels of the underweight, normal weight, and obese groups were $51.92{\pm}9.39mg/dL$, $59.20{\pm}13.53mg/dL$, and $43.00{\pm}8.98mg/dL$, respectively, showing that the obese subjects had significantly lower HDL-cholesterol levels as compared to the subjects in the other groups (p<0.05). The HDL-C/LDL-C ratios of the underweight ($0.52{\pm}0.45$) and normal weight ($0.59{\pm}0.23$) groups were higher than the ratio of the obese group ($0.41{\pm}0.06$). Total cholesterol were positively correlated with LDL-cholesterol (r=0.768, p<0.01), but triacylglycerol were adversely correlated with HDL-cholesterol. In conclusion, our results show that college-aged women in Seoul should be encouraged to amend their overall dietary habits, make a dietary plan that fits their individual needs, and maintain an effective exercise schedule.