• Macromolecular Research
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• v.17 no.11
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• pp.829-841
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• 2009

This study introduces a specified group-contribution method for predicting the phase equilibria in polymer solutions. The method is based on a modified double lattice model developed previously. The proposed model includes a combinatorial energy contribution that is responsible for the revised Flory-Huggins entropy of mixing, the van der Waals energy contribution from dispersion, a polar force and specific energy contribution. Using the group-interaction parameters obtained from data reduction, the solvent activities for a large variety of mixtures of polymers and solvents over a wide range of temperatures can be predicted with good accuracy. This method is simple but provides improved predictions compared to those of the other group contribution methods.

• Journal of Preventive Medicine and Public Health
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• v.38 no.1
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• pp.107-116
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• 2005

Objectives : We analyzed the changes from 1996 to 2002 in distributive equity of the contribution burden in the Korean National Health Insurance. Methods : The study subjects were a total of 8,923 employee households and a total of 7,296 self-employed households over the period from 1996 to 2002. Those were the households meeting the two criteria as completing each annual survey and having no change in the job of head of the household during that period from the raw data of the Household Income and Expenditure Survey annually conducted by the Korean National Statistical Office. The unit of analysis was a household, and this was the standard for assessing the contribution that is now applied on a monthly basis. Deciles Distribution Ratio, Contribution Concentration Curve and Contribution Concentration Index were estimated as the index of inequality. Multiple regression analysis was conducted to compare the annual ability-to-pay elasticity of the contribution to the reference year of 1996 for three groups (all households, the employee households, and the self-employed households). Results : For the index of inequality, the distributive equity of contribution was improved in all three groups. In particular, the employee group experienced a substantial improvement. Using multiple regression analysis, the ability-to-pay elasticity of the contribution in the employee group significantly increased ($\beta$=0.232, p<0.0001) in the year 2002 as compared to the reference year of 1996. The elasticity in the self-employed group also significantly increased ($\beta$=0.186, p<0.05), although its change was smaller than that in the employee group. Conclusions : The employee group had a greater improvement for the distributive equity of the contribution burden than the self-employed group. Within the observation period, there were two important integration reforms: one was the integration of 227 self-employed societies in 1998 and the other was the integration of 139 employee societies in 2000. We expected that the equity of the contribution burden would be improved for the self-employed group since the integration reform of 1998. However, it was not improved for the self-employed group until the year 2000. This result suggests that capturing exactly the beneficiaries' ability-to-pay such as income is the precedent for distributive equity of the contribution burden, although a more sophisticated imposition standard of contribution is needed.

• Journal of Nutrition and Health
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• v.36 no.3
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• pp.319-326
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• 2003

The purposes of this study were to : (a) analyze the menus of food service operations using the menu analysis techniques of Kasavana & Smith, Miller, Merricks & Jones, Pavesic and Uman, (b) closely examine the characteristics of the five analysis techniques. Calculations for the menu analysis were done by computer using the MS 2000 Excel spreadsheet program. Menu mix% and unit contribution margin were used as variables by Kasavana & Smith, sales volume and food cost% by Miller, sales volume and cash contribution by Merrick & Jones, weighted contribution margin and food cost% by Pavesic, and total cash contribution and unit contribution margin by Uman. In each case, a four-cell matrix was created, and menu items were located in each according they achieved high or low scores with respect to two variables. Items that scored favorably on both variables were rated in the top category (e.g., star, prime, signature, group A, winner) and those that scored below average on both were rated in the lowest category (e.g., dog, problem, loser, group D, loser). While the 3 methods of Kasavana & Smith, Miller, Merrick & Jones focus on customers' viewpoints, the others consider the managers' viewpoints. Therefore, it is more likely to be desirable for decision-making on menus if the menu analysis technique chosen is suited to its purpose.

• Korean Journal of Community Nutrition
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• v.25 no.1
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• pp.32-47
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• 2020

Objectives: Calcium (Ca) is an insufficiently consumed nutrient, whereas phosphorus (P) intake has exceeded the recommended intake level in Korea over the past decade. The purpose of this study was to analyze dietary Ca and P intakes and their contribution rate according to dish groups. Methods: A 24-hour dietary recall survey of 640 healthy adults (aged 19-69 years) was undertaken twice in four Korean provinces. Dietary Ca and P intakes and their rates of contribution from 31 major dish groups were analyzed and compared by gender, age group, and region. Results: The average Ca and P intakes of the subjects were 542.1 ± 222.2 mg/d and 1,068.3 ± 329.0 mg/d, respectively. The intakes of Ca and P as percentages of recommended nutrients intake (RNI%) were 71.7 ± 29.8% and 152.6 ± 47%, respectively, and the percentages under the estimated average requirement were 60.3% for Ca and 3.8% for P. The RNI% of Ca was not significantly different between males and females, but was significantly higher in subjects in the sixties age group than in other age groups and was significantly lower in the Korean capital than in other regions. The RNI% of P did not significantly differ by gender or age groups, but it was significantly higher in the capital than in Gyeong-sang. The five major dish groups contributing to Ca intake (contribution rate) were milks/dairy products 69.2 ± 109.2 mg/d (12.6%), soups 55.6 ± 69.6 mg/d (10.1%), stir-fried foods 53.1 ± 70.7 mg/d (9.7%), stews 43.4 ± 85.4 mg/d (7.9%), and kimchi 38.4 ± 31.8 mg/d (7.0%). The five major dish group contributing to P intake (contribution rate) were cooked rice 160.7 ± 107.1 mg/d (14.9%), stir-fried foods 88.5 ± 89.4 mg/d (8.2%), soups 76.7 ± 85.8 mg/d (7.1%), one-dish meals 63.3 ± 94.4 mg/d (5.9%), and stews 62.6 ± 89.3 mg/d (5.8%). The dish groups contributing to Ca and P intakes differed somewhat by gender, age group, and region. Conclusions: Programs to improve the nutritional status of Ca and P intakes should consider the differences in Ca and P contribution rates by dish groups as well as by gender, age group, and region.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.61.4-62
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• 2017

In this study we have made a statistical investigation on the kinematic classification of coronal mass ejections (CMEs) using about 4,000 SOHO/LASCO CMEs from 1996 to 2015. For this we use their SOHO/LASCO C3 data and exclude all poor events. Using the constant acceleration model, we classify these CMEs into three groups: Acceleration group, Constant Velocity group, and Deceleration group. For classification we adopt four different methods: Acceleration method, Velocity Variation method, Height Contribution method, and Visual Inspection method. Our major results are as follows. First, the fractions of three groups depend on the method used. Second, the results of the Height Contribution method are most consistent with those of the Visual Inspection method, which is thought to be most promising. Third, the fractions of different kinematic groups for the Height contribution method are: Acceleration (35%), Constant speed (47%), and Deceleration (18%). Fourth, the fraction strongly depend on CME speed; the fraction of Acceleration decreases from 0.6 to 0.05 with CME speed; the fraction of Constant increases from 0.3 to 0.7; the fraction of Deceleration increases from 0.1 to 0.3. Finally we present dozens of CMEs with non-constant accelerations. It is found that about 40 % of these CMEs show quasi-periodic oscillations.

• Journal of the Korean Geosynthetics Society
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• v.20 no.1
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• pp.21-34
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• 2021

In this study, to solve a problem that cannot consider the contribution effect of each layers when the apparent earth pressure in homogeneous ground is applied to multi-layered ground, the measured earth pressures at World were investigated and analyzed. It has been confirmed that the apparent earth pressure in mulit-layered ground is different from single ground and that the extra layer's contribution to the earth pressure cannot be considered. The conventional method of calculating the apparent earth pressure for single ground was extended to mulit-layered ground, and proposed and verified the applicable method for both single and mulit-layered ground. The proposed methods predicted the earth pressure closer to the measurements at the excavation depth of 0.1Z/H or below, and the prediction reliability was evaluated to be better than the conventional method. Among the proposed methods, the method of considering the area ratio of the active failure has a geotechnical validity and predicts the most similar results to the actual earth pressure. To confirm the applicability of the proposed methods, it was presented by comparing and analyzing the results of the proposed methods with the conventional method for the actual case.

• Journal of Korean Clinical Nursing Research
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• v.23 no.1
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• pp.100-109
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• 2017

Purpose: Nurses' resilience plays an important role in overcoming the challenges that nurses often encounter at clinic, and many factors have been examined which influence on nurses' resilience levels. Through this study, those factors were systematically searched and quantitatively synthesized. Methods: In order to find relevant studies, both English and Korean academic databases were searched, and, finally, a total of 33 articles were identified and included in this analysis. Results: The effect size on the protective variables was large and that of the risk variables was medium. In the protective variable group, the job variable group showed a larger effect size compared to the organizational variable group. Among the protective variables, compassion satisfaction showed the highest contribution on enhancing the resilience level of nurses. In the risk variable group, the personal variable group showed the highest effect size, which was followed by the organizational and job variables. Among the risk variables, the personal stress response showed the highest contribution to decreasing the level of resilience of nurses. Conclusion: This study provides a meaningful data for future studies in terms of developing evidence-based interventions to enhance the levels of resilience among Korean nurses.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.3
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• pp.107-113
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• 2021

PURPOSE: Selective strengthening of the transverse abdominis muscle (TrA) during abdominal hollowing makes an important contribution to the stability and control of the spine. This study examined the effects of abdominal hollowing exercise (AHE) according to the visual feedback method on the external oblique, internal oblique, and transverse abdominis muscles. METHODS: Twenty healthy subjects were assigned randomly to an AHE with visual feedback from real-time ultrasound image (group A, n = 10), AHE with visual feedback with pressure biofeedback unit (group B, n = 10). Both groups underwent 20 min of AHE with visual feedback once daily, five days/week for two weeks. The changes in the muscle thickness of the TrA, internal oblique abdominal muscle (IO), and external oblique abdominal muscle (EO) were measured by ultrasonography. RESULTS: The thickness of TrA was changed significantly in both groups (p < .05). However, the lowest minimal detectable changes were achieved in Group A. The thickness of the IO and EO muscles in group A was changed significantly, but there were no significant changes in group B. CONCLUSION: Both visual feedback methods were effective for strengthening the TrA muscles selectively. Nevertheless, AHE with visual feedback using real-time ultrasound images may be more useful in trA muscle contraction.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.11a
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• pp.102-117
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• 2002

The general design practice for piled footings is based on the assumption that the piles are free-standing, and that all the external loads are carried by the piles, with any contribution of the footing being ignored. This approach is not reasonable, because the footing itself is actually in direct contact with the soil, and thus carries a significant fraction of the loads. In the case of not considering the bearing capacity of footing, the bearing capacity of group piles can be evaluated conservatively in the designing the group piles. There are a number of reasons why the idea of piled raft design with considering the capacity of footing has not become widely used. One of the reasons is the lack of reliable calculation methods for estimating the behavior of piled raft. In this study the bearing capacity, settlement, load distribution, etc. of piled raft footing are studied.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.800-811
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• 2014

Recent developments in the prediction of the contribution of windnoise to the interior SPL have opened a realm of new possibilities in terms of i) how the convective and acoustic sources terms can be identified, ii) how the interaction between the source terms and the side glass can be described and finally iii) how the transfer path from the sources to the interior of the vehicle can be modelled. This work discusses in details these three aspects of wind noise simulation and recommends appropriate methods to deliver required results at the right time based on i) simulation and experimental data availability, ii) design stage at which a decision must be made and iii) time available to deliver these results. Several simulation methods are used to represent the physical phenomena involved such as CFD, FEM, BEM, FE/SEA Coupled and SEA. Furthermore, a 1D and 2D wavenumber transformation is used to extract key parameters such as the convective and the acoustic component of the turbulent flow from CFD and/or experimental data whenever available. This work focuses on the validation of the wind noise source characterization method and the vibro-acoustic models on which the wind noise sources are applied.