• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.11
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• pp.1363-1370
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• 1999

A study of scaling and heat transfer has been carried out for a vertical tube evaporator in which $CaSO_4$ saturated water flows upward. Experimental apparatus including vacuum chambers and heaters has been designed and manufactured to study scaling phenomena for three different pressures(1atm, 0.27atm and 0.16atm). Overall heat transfer coefficients have been measured and shown to decrease with time as scaling proceeds. After the end of experiments, the vertical tube has been cut to measure the thickness of scale at different heights. Below the height where the bulk fluid temperature does not reach saturated temperature, the thickness of scale increases, however, beyond that height occurring saturated condition, the thickness does not vary much or even decreases a little. The measured fouling resistances also support these variations of scale thickness.

• Environmental and Resource Economics Review
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• v.9 no.5
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• pp.973-997
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• 2000

The carbon tax is one of several measures to reduce the green-house gases emitted from burning the fossil fuels, which has been much discussed internationally. The analyses of the effects of a carbon tax on individual countries have been carried out by applying the computable general equilibrium(CGE) models, especially models with the assumption of non-existence of scale economies. However, the introduction of scale economies to CGE models changes the simulation results drastically. In this paper, two CGE models are used to compute and compare the economic and $CO_2$ reduction effects of a carbon tax, one of with is the model with scale economies and the other is without scale economies. One of main results is that the analysis using the CGE model without scale economies may underestimate the effects of a carbon tax on GDP and reducing the emission of $CO_2$.

• International Journal of Fluid Machinery and Systems
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• v.4 no.2
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• pp.229-234
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• 2011

For Lift-type Vertical Axis Wind Turbine (VAWT), it is difficult to evaluate the performance through the scale-model wind tunnel tests, because of the scale effect relating to Reynolds number. However, it is beneficial to figure out the critical value of Reynolds number or minimum size of the Lift-type VAWT, when designing this type of micro wind turbine. Therefore, in this study, the performance of several scale-models of Lift-type VAWT (Reynolds number : $1.5{\times}10^4$ to $4.6{\times}10^4$) was investigated. As a result, the Reynolds number effect depends on the blade chord rather than the inlet velocity. In addition, there was a transition point of the Reynolds number to change the dominant driving force from Drag to Lift.

• Anxiety and mood
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• v.10 no.2
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• pp.137-142
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• 2014

Objective : The aim of this study was to investigate the relationship among daytime sleepiness, depressive symptoms, anxiety symptoms, and stress response of students in a university Methods : A total of 557 students were recruited in this study. The participants filled out stress response inventory, Epworth sleepiness scale, overall anxiety severity and impairment scale, and quality of life scale. Results : Excessive daytime sleepiness group showed higher scores in all factors in stress response inventory, overall anxiety severity and impairment scale, and quality of life scale. Sleepiness might be correlated with somatization and depression and anger in Stress response inventory. Conclusion : Excessive daytime sleepiness group exhibited poor quality of life scale. Screening about overall quality of sleep, such as mood and anxiety should be considered for students in a university.

• Journal of the Korean Home Economics Association
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• v.36 no.12
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• pp.129-143
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• 1998

The purpose of this study was to develop a Korean Coping Strategy Scale and to examine coping characteristics of Korean housewives form urban low-income families using this Scale. Two hundred and forty mothers were either interviewed or filled out this Coping Strategy Scale and Demograpic Information Questionnaire. The Coping Strategy Scale consisted of 14 items under 4 dimensions of problem-solving, support-seeking, emotion-regulation/explosion, and abandonment. Item analysis and construct validation were found acceptable. The alpha coefficient of the Scale was 73. The results showed that the mothers used problem-solving most as a coping strategy, followed by supportseeking and emotion-regulation/explosion. Abandonment coping strategy was used least frequently. The demographic variables of mother's and their husbands' age, duration of marriage, income and expenditure per moth were significantly related to mothers' coping strategies.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.125-128
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• 2006

Many research have been carried out concerned with the flexural performance of FRP composite in a various ways. Most of them, however, have used a small-scale specimen, so haven't been fully verified by full-scale model test. In this study, a full-scale RC beam model test for flexural strengthening with CFRP composites has been performed in order to verify test results obtained through a series of small-scale model test with respect to FRP stiffness affecting strengthening performance in the previous studies. A total of 4 specimens have been manufactured including control beam. The specimens strengthened with CFRP composites consist of 3 different CFRP stiffness with 2 types of CFRP composite. Consequently, the purpose of this study is to estimate influence of the size effect of specimens and FRP stiffness on the flexural performance. As a result, the effective strain of FRP composite is inversely proportional to FRP stiffness and ensures the same performance with small-scale model test.

• The Journal of Korean Physical Therapy
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• v.28 no.6
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• pp.364-368
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• 2016

Purpose: The purpose of this study is to investigate effects of psychological factors on Schroth exercise and Pilates exercise to female high school students with idiopathic scoliosis. Methods: Sixteen subjects with over 20 of Cobb's angle were randomly divided into Schroth exercise group (SEG, n=8) and Pilates exercise group (PEG, n=8). Both training programs were carried out 3 day a week for 12 weeks. Psychological factors were measured using depression scale, self esteem scale and body esteem scale. Results: Both groups showed significant differences in depression scale, self esteem scale and body esteem scale. Schroth exercise group showed greater improvement than Pilates group. Conclusion: Having correct body image affects psychological factors to growing students. Schroth exercise is more effective method to physical and psychological approach of idiopathic scoliosis.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.967-987
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• 2020

A numerical analysis is carried out for the marine propellers in open water conditions to investigate the effect of the wall treatments in model and full scale. The standard wall function to apply the low of the wall and the two layer zonal model to calculate the whole boundary layer for a transition phenomenon are used with one turbulence model. To determine an appropriate distance of the first grid point from the wall when using the wall function, a formula based on Reynolds number is suggested, which can estimate the maximum y+ satisfying the logarithmic law. In the model scale, it is confirmed that a transition calculation is required for a model scale propeller with low Reynolds number that the transient region appears widely. While in the full scale, the wall function calculation is recommended for efficient calculations due to the turbulence dominant flow for large Reynolds number.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.518-520
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• 2007

Since all essential property of semiconductor materials are structure-sensitive, the understanding of the deformation mechanism and the deformed structure which can be formed in the nanometer-scale devices is very crucial. To investigate the deformation mechanism and the corresponding structures, nanometer-scale contact loading simulations are carried out using molecular dynamics in silicon and gallium-arsenide.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.69-69
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• 2004

The scale of photospheric convection in red giants is generally associated, by analogy with the Sun, with the atmospheric pressure scale height and the thickness of the superadiabatic transition layer(SAL). As pointed out by Schwarzschild(1975), both of these quantities are relatively much larger in terms of the stellar radius in a red giant then in the Sun. (omitted)