• Nutritional Sciences
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• v.7 no.4
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• pp.208-213
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• 2004

In this study, we examined the effects of dietary 1,3-diacylglycerol (DG) compared to conventional triacylglycerol (TG) oil on the postprandial response of total and chylomicron TG, glucose, insulin, and free fatty acid (FFA). This study was conducted using a cross-over design. Ninety subjects participated in the high-fat meal tolerance test where they were randomly assigned to consume two experimental sandwiches containing mayonnaise with TG or DG oil with a seven-day interval. Blood samples were collected before ingestion and at 2, 3, 4 and 6 hr time point after ingestion and analyzed for total and chylomicron TG, glucose, insulin, FFA and phospholipid fatty acid composition. Both TG and DG ingestion had similar effects on postprandial TG response, but a different response from chylomicron TG. Compared with the TG group, TG levels were significantly lower only at 6 hr time point in the DG group. On the other hand, chylomicron TG rose steeply at 2 hr time point and decreased faster in this group. Also, the adjusted value to fasting levels was the same as the unadjusted level. Fasting levels and net differences in insulin were significantly lower at 3 hr time point where chylomicron TG levels were significantly lower in the DG group. But those of glucose and FFA in the TG and DG groups did not differ significantly. Fasting and postprandial levels of fatty acid composition in serum phospholipids in the two groups did not differ significantly. In conclusion, this study indicated that one could reduce the magnitude of postprandial lipemia without influencing glucose metabolism by consumning DG oil as a substitute for TG oil. Based on the correlation of coronary artery disease and postprandial lipemia, dietary DG ingestion might have a beneficial effect in treating such a disease. Further studies are required to clarify the long-tenn effects of dietary DG on blood lipid levels in humans.

• Journal of Nutrition and Health
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• v.47 no.4
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• pp.229-235
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• 2014

Purpose: The objective of this study was to investigate the effects of xyloologosaccharide (XOS)-sugar mixture on glycemic index (GI) and blood glucose in human subjects. Methods: Randomized double-blind cross-over studies were conducted to examine the effect of sucrose with 14% xyloologosaccharide powder (Xylo 14) and sucrose with 20% xylooligosaccharide powder (Xylo 20) on GI and postprandial glucose response at 15, 30, 45, 60, 90, and 120 min. Results: GIs of Xylo 14 and Xylo 20 were $60.0{\pm}23.5$ classified within medium GI range, and $54.3{\pm}17.7$ within low GI range, respectively. Xylo 14 and Xylo 20 showed significantly lower area under the glucose curve (AUC) for 0-15 min (p = 0.0113), 0-30 min (p = 0.0004), 0-45 min (p < 0.0001), 0-60 min (p < 0.0001), 0-90 min (p < 0.0001), and 0-120 min (p = 0.0001). In particular, compared with glucose, the blood glucose levels of Xylo 14 and Xylo 20 were significantly lower at every time point between 15 and 120 min. Conclusion: The results of this study suggested that Xylo 14 and Xylo 20 had an acute suppressive effect on GI and the postprandial glucose surge.

• Journal of Nutrition and Health
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• v.49 no.3
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• pp.144-152
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• 2016

Purpose: This study was conducted in order to develop morning bread using powdered citrus peels and to examine the effect of its several biological activities for 12 weeks in overweight adults ($$BMI{\geq_-}23$$) living in dormitories of Chonbuk National University. Methods: Control bread was prepared using the same formula except for replacing the wheat flour with 3% citrus peel powder. Subjects were classified according to two groups: Intake group of 3% citrus peel powder fortified morning bread (n = 30) and general morning bread (n = 30). Results: The results of our study showed no significant effects of citrus peel powdered morning bread on anthropometric indices and biochemical characteristics among overweight adults. Despite the slight reduction in total-cholesterol, LDL-cholesterol, GOT, and GPT (p < 0.05), no significant differences in changes of these values were observed between the two groups. Conclusion: The short duration of our intervention might have resulted in the lack of any significant effect. Therefore, conduct of further studies with longer duration is warranted in order that the results from this study can be utilized as a basis for the development of food products with citrus peel powder.

• Environmental and Resource Economics Review
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• v.25 no.2
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• pp.199-228
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• 2016

This study investigates the effects of economic factors and forest environments on rural residential area development in seven north central states of the U.S. by focusing on the relative importance of not only economic factors but also forest environments by forest type as core drivers of residential development. An empirical model of locations and magnitudes of population changes since 1950 in the north central region is first constructed, and then a panel model with fixed effects for counties is used to explain population growth by age group over time at the county level. Then a set of three equations is estimated for three major age groups, and a cross-sectional model is estimated for the last time period that regresses county-level environmental amenity variables on fixed effects coefficients for counties. Finally, an equation explaining changes in rural housing density is estimated. The results imply that immigrant age is a key factor influencing the choice of the place of residence and that the effects of environmental amenity factors on population growth and subsequent housing development in a county vary according to the age group.

• Korean System Dynamics Review
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• v.1 no.2
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• pp.5-31
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• 2000

The summit meeting of the South North Korean leaders was a turning point in the relationships between the two countries. It was followed by the Red-Cross Meeting, Minister-Level Meeting, economic agreements, which have increased the relationship more colorful in both quantities and qualities. However, the half-century period for separation was too long to overcome all the problems by only one event. The two countries have quite different social systems; one politically strong person is governing the North, while many interest groups are involved in political decision making processes in the South. In short, it would take a long time to settle down all the problems residing between the two countries. A system dynamics model is developed to describe the long term dynamics of the relations between the South and North Koreas. As a first attempt, the model focuses only on the diplomatic meeting issues between the South and North. The model aggregates diplomatic issues into 5 categories; economic issues, security issues, infrastructure, cultural issues, and past problems. It assumes that there would not be any dramatic changes between the two countries. It is a conceptual model composed of around 200 variables, and should not be used as a forecast tool. However, it captures most of the logics discussed in the papers and conferences concerning the South and North Korea relations. Many sensitivity studies and Monte Carlo simulations have shown that the simulation results matches with mental models of experts; that is the model can be used as a learning tool or as a secondary opinion until the data required by the model is collected. In order to analyze the current situation, five scenarios are simulated and analyzed; the functional approach, the conditional approach, the balanced approach, the circumstantial approach, and the strategic approach. The functional approach represents that the South makes efforts in the area where the possibility of agreement is high for the next 10 years. The conditional approach is a scenario where the South impose all difficult issues as conditions for resolving other diplomatic issues. The balanced approach is resolving the five issues with the same priorities, while the circumstantial approach is resolving issues which seem to be resolved easily. Finally, another optimum approach has been seek using the system dynamics model developed. The optimum strategy (it is named as the strategic approach) was strikingly different from other four approaches. The optimum strategy is so complicated that no one could find it with mental model(or by just insights). Considering that the system dynamic model used to find the optimum is a simplifind (maybe over simplified) version of the reality, it is concluded that a well designed system dynamics model would be of great help to resolving the complicated diplomatic problems in any kind.

• Korea journal of population studies
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• v.33 no.3
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• pp.1-30
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• 2010

This study examines difference in age at marriage between spouses and more importantly, investigates into the economic and social factors affecting the ratio or probability of wife-older marriages. Empirical analysis is carried out by applying both logit model and multinomial logit model to an independently pooled cross-section over 2004-2007. The data was collected mainly from the micro data service system of the Statistics Korea. Empirical results indicate that a wife-older marriage was more likely as a wife was more educated and was a larger income earner than a husband. On the other hand, a wife's educational and income level themselves had few systematic relationships with the probability of a wife-older marriage. The probability of a wife-older marriage tended to decrease(increase) when a husband's(a wife's) marriage was the second' The study calculates the average marginal effect of difference in the income level between spouses on the probability of a wife-older marriage, which is -0.007. That is, the probability of a wife-older marriage increases by 0.7% as a husband's income level is 1 million Korean Won less than a wife's. This results presents empirical evidence against widely distributed misconception on wife-older marriage in the mass media.

• The Journal of Advanced Prosthodontics
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• v.1 no.2
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• pp.85-90
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• 2009

STATEMENT OF PROBLEM. Over the years, resin-bonded fixed partial dentures (RBFPDs) have gone through substantial development and refinement. Several studies examined the biomechanics of tooth preparation and framework design in relation to the success rate of RBFPDs and considered retention and resistance form essential for increase of clinical retention. However, these criteria required preparations to be more invasive, which violates not only the original intentions of the RBFPD, but may also have an adverse effect on retention due to loss of enamel, an important factor in bonding. PURPOSE. The object of this in vitro study was to compare the dislodgement resistance of the new types of RBFPDs, the conventional three-unit fixed partial denture, and conventional design of RBFPD (Maryland bridge). MATERIAL AND METHODS. Fifty resin mandibular left second premolars and second molars were prepared on dentiforms, according to the RBFPD design. After model fabrication (five group, n = 10), prostheses were fabricated and cemented with zinc phosphate cement. After cementation, the specimens were subjected to tensile loading at a cross head speed of 4 mm/min in a universal testing machine. The separation load was recorded and analyzed statistically using one-way analysis of variance followed by Duncan's multiple range test. RESULTS. Group V, the pin-retained RBFPDs, had the highest mean dislodgement resistance, whereas specimens of group II, the conventional RBFPDs, exhibited a significantly lower mean dislodgement resistance compared to the other 4 groups (P <.05). There were no significant differences between group I, III, and IV in terms of dislodgement resistance (P>.05). Group V had the highest mean MPa (N/$mm^2$) (P <.05). There was no significant difference between groups I, II, III and IV (P > .05). CONCLUSION. Within the limits of the design of this in vitro study, it was concluded that: 1. The modified RBFPDs which utilizes the original tooth undercuts and requires no tooth preparation, compared with the conventional design of RBFPDs, has significantly high dislodgement resistance (P < .05). 2. The modified RBFPDs which utilizes the original tooth undercuts and requires minimal tooth preparation, compared with the conventional FPDs, has significantly no difference in retention and dislodgement resistance)(P>.05). 3. The pin-retained FPDs showed a high dislodgement resistance compared to the conventional three-unit FPDs (P<.05).

• Korea journal of population studies
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• v.28 no.2
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• pp.165-182
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• 2005

The main purposes of this study are to describe the elderly dementia, and to explore characteristics of the elderly dementia among the aged 65 and over in Daegu area. In this study, 1,120 subjects which were 0.6 percent of the population were selected and face-to-face interviews were conducted. The face-to-face interviews were conducted from July 1, 2004 to August 31, 2004. KMMSE was introduced to measure the status of the interviewees' dementia. The findings of this study are as follows: 8.9 percent of respondents turns out to be dementia patients. Among the dementia patients, 52.5 percent are mild dementia patients, 35.0 percent are mid-level symptoms and 12.5 percent are severe symptoms of dementia patients. Cross-tabulation analyses and logistic regression analysis were introduced to explore the demographic, living, and behavioral differentials of the elderly's dementia. According to the logistic regression analysis, it turns out that white educational attainment, participating in the leisure activities for both physical exercise and mental activities, having meals regularly, adequate amount of meals, and high economic status decrease the odds ratio of elder dementia among the elderly who are 65 and above in Daegu area and are statistically significant. On the other hand, age increases the odds ratio of the elder dementia of the elder among Koreans above 65 in Daegu area. Finally, policy implications and some suggestions for the improvement of the elder dementia are introduced and discussed.

• Korea journal of population studies
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• v.25 no.1
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• pp.257-289
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• 2002

In this study we analyse how the tobacco prices have an effect on the national health. The level of tobacco price will fluctuate its consumers demand and eventually affect the national health status. We estimate tobacco consumption function as well as households'demand system in which tobacco and health expenditure functions are included. Demand elasticities are estimated and evaluated in order to find future policies to improve the national health by controlling the national tobacco consumption There are two econometric approaches app1ied in this study. The lent tobacco demand analysis method is mm tobacco consumption function model. Using national indices of tobacco price, tobacco consumption and other related variables, tobacco consumption function is estimated. The other is micro demand system analysis by using Korean urban households expenditure data during the period of 1991 to 1999. The own price elasticity which is estimated from national tobacco demand per capita is -0.19 for all people and -0.176 for the adults over 18, which means 100% price increase will cause decease of tobacco demand at 19% and 17.6% per each The cross vice elasticity which is estimated between tobacco and health expenditure of urban households demand system is -0.2328, which implies 100% of tobacco price increase will decrease 23.28% of health expenditure. The low price elasticities imply that tobacco price increase will increase total tobacco sales volume. 100% of tobacco price increase will bring about 79% increase of total tobacco sales volume according to our scenario. Korea's tobacco demand is negatively responsive to fluctuations in its price. The health expenditure is also negatively relatedto the tobacco price fluctuation. These empirical outputs could be utilized as the basis of government's tax policy to control national tobacco consumption in the future.

• Korean Journal of Labor Studies
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• v.24 no.3
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• pp.35-71
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• 2018

The purpose of this study is to examine which job-related factors are associated with presenteeism, which is defined as attending work while ill. Although presenteeism is a relatively new concept in academic research, it should be regarded as an important social issue in that presenteeism threatens employees' job prospects and quality of life as well as it causes loss of work productivity. I analyzed a cross-sectional survey of 24,571 wage workers over 15 from the fourth wave of the Korean Working Conditions Survey in 2014. Five logistic regression models were analyzed on experience of presenteeism, and work hours and private life, occupational environment, job insecurity, rewards and welfare were assessed as key predictors of presenteeism. I found that 1) work hours with bad fit with private life, 2) high level of work time-pressure, and low job satisfaction 3) job insecurity, and 4) low benefits are associated with experience of presenteeism. The findings are fairly consistent with the theory of job-person mismatch, which explains that workers tend to preserve their personal resources by going to work while ill (presenteeism) when job demands or work conditions do not match with their level of personal expectation and, thus, workers are afraid of loss of personal resources. Presenteeism influences worker's long-term health and quality of life negatively as well as causes serious social costs. Therefore, we need organizational efforts to prevent the negative effects of presenteeism on society as well as workers.