• Journal of Electrochemical Science and Technology
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• v.15 no.2
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• pp.276-290
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• 2024

A study of the transition from transitory state to steady state in DSSCs based on natural dyes is presented; cochineal was used as dye and Li⁺, Na⁺, and K⁺ were the ions added to the electrolyte. The photocurrent profiles were obtained as a function of time. Several DSSCs were prepared with different cations and their role and the transitory-to-steady transition was determined. A novel hybrid charge carrier source model based on the Heaviside function H(t) and the Lambert-Beer law, was developed and applied to analysis of the transient response of the output photocurrent. Additionally, the maximum effective light absorption coefficient α and the electronic extraction rate κ for each ion were determined: ${\alpha}_{Li^+,Na^+,K^+}\,=\,(0.486,\,0.00085,\,0.1126)\,cm^{-1}$, and also the electronic extraction rate ${\kappa}^{Li^+,Na^+,K^+}_{ext.}\,=\,(1410,\,19.07,\,19.69)\,cm\,s^{-1}$. The impedance model using Fick's second law was developed for carrier recombination to characterize the photocurrent.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.55-62
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• 2017

The purpose of this study is to investigate the transitory and permanent growth effects of human capital of the Korean economy based on the analysis of the New Normal Era during the period 1970-2014. For the transitory effects, we found out that all the coefficients of capital and labor are significant above the 5% level, whereas the coefficients of labor and human capital are significant only at the 10% level during the period 1999~2014. In particular, in the case of 1% increase in the human capital, the actual growth rate raised up with the rate of 0.15% over a 45-year period. For the permanent growth effects, the coefficients of capital and labor are significant above the 5% level. Furthermore, sum of the coefficients of the capital and labor showed approximately 0.96~0.99, approaching to a unit, which implies that there is a constant returns scale with respect to these inputs. In particular, the coefficient of human capital at 0.064 is significant at the 10% level. This implies that the permanent growth effect of an additional index of human capital is about 0.64% the previous 45-year period.

• Land and Housing Review
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• v.13 no.4
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• pp.45-53
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• 2022

This paper investigates empirically the lead-lag relation between the 'apartment price index' and 'Internet search volume'. This study uses Naver Trend Index as a proxy for Internet search volume. An increase in Internet search volume on the apartment price index indicates an increase in people's attention to an apartment. Different from previous studies exploring the relation between 'the released price index of the apartment' and 'Naver Trend Index', this study investigates the relation of the Naver Trend Index with 'the fundamental price component of an apartment' and 'the transitory price component of an apartment', respectively. The results of the Granger causality test reveal that there are bidirectional Granger causalities between the 'released price' and Naver Trend Index. In addition, the 'fundamental price component of an apartment' and Naver Trend Index have a feedback relation, while 'the transitory price component of an apartment' Granger causes the Naver Trend Index uni-directionally. The impulse response function analysis indicates that the shock of apartment prices increases Naver Trend Index in the first month. Overall, The close relationship between apartment prices and Naver Trend Index suggests that increases in the movement of apartment prices are positively associated with public attention on the apartment market.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.582-586
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• 2004

The purpose of this study is to examine the lead-lag relationship between volatility and returns in high frequency stock market data to see the validity of two hypotheses that explain volatility asymmetry. Specifically, wavelet analysis is applied to decompose the volatility process into permanent and transitory components and then each component is investigated in conjunction with returns. The results from cross-correlation analysis between volatility and returns support the leverage effect hypothesis rather than the volatility feedback hypothesis in all cases.

• Korean Journal of Social Welfare
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• v.65 no.3
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• pp.183-206
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• 2013

Using Korean Labor and Income Panel Study (wave 1~11) database, this study analyzed the poverty duration of the poor as a whole and by households' characteristics. For this purpose, I first estimated poverty exit rates and reentry rates applying discrete-time hazard model to the sample, and then calculated poverty duration combining these two probability rates. The results show that about a half of poor households are transitory (short-term) poor with 1~2 years of poverty duration. A quarter is chronic (long-term) poor lasting for 5 or more years of poverty duration. The remained quarter can be categorized as the recurrent or mid-term poor. The socioeconomic characteristics of households greatly affect poverty duration. Long-term poverty is prevalent among female-head households, elderly households, single households, or households headed by a person with a lower level of education. If households' heads do not work, or work as temporary or daily-employed workers, the poverty duration tends to be longer. The findings suggest that the poor consist of various social classes with different characteristics. Efficient anti-poverty policy should be based on thoroughly identifying the specific characteristics and needs of each class.

• Journal of Labour Economics
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• v.25 no.2
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• pp.1-32
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• 2002

This paper investigates how real wages adjust to regional and cyclical shocks in the Korean labor market. Major findings are as follows. First, like most longitudinal studies in this literature, we find that real wages are strongly procyclical and more procyclical for men than for women. Second, consistent with the theory prediction of efficiency wages, both permanent and transitory components of real wages are negatively correlated with the local unemployment rate. Third, when overall and local unemployment rates compete in a wage equation (our preferred specification), current wages are dominantly affected by the overall rate, and the effect of the local rate is rather small. This rejects the Blanchflower and Oswald's hypothesis that wages are primarily determined by local labor market conditions. Finally, no lagged effects on wages are detected in the overall or local unemployment rate.

• Korean Journal of Social Welfare
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• v.61 no.1
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• pp.57-79
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• 2009

This study analyzes the effect of poverty on child development outcomes including academic achievement, self-esteem, depression/anxiety, attention problems, aggression, and delinquency. The poverty experiences among elementary school children are longitudinally observed during 3 years between the 4th grade and the 6th grade. When development outcomes are compared among persistently poor children, transitory poor children, and non-poor children, academic achievement is found to be significantly different. The analyses of the relationships between the poverty status and developmental trajectories show that academic achievement among non-poor children has improved over time, while the level of poor children's achievement has decreased. The result also shows that problematic behaviors such as attention problems, aggression, delinquency has improved over time among all the children. Yet, the gap between poor and non-poor children has not decreased. The multivariate analyses indicate that the effect of poverty remains statistically significant only for academic achievement after children's individual and familial characteristics are controlled. Past experiences of poverty in addition to the current poverty affect academic achievement and persistent poverty has a stronger effect than transitory poverty on academic achievement, although the findings are not consistent across all the estimated models.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.525-528
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• 2004

The photoluminescence (PL) emission of Si nanocrystals synthesized by 400 keV Si ion implanted in $SiO_2$ is studied as a function of ion dose and annealing time. The formation of nanocrystals at around 600 nm from the surface was confirmed by RBS and HRTEM, and the Si nanocrystals showed a wide and very intense PL emission at 700-900 nm. The intensity of this emission showed a typical behaviour with a fast transitory increase to reach a saturation with the annealing time, however, the red shift increased continuously because of the Ostwald ripening. The oversaturation of dose derived a decrease of PL intensity because of the diminishment of quantum confinement. A strong enhancement of PL intensity by H passivation was confirmed also, and the possible mechanism is discussed.

• Journal of Mechanical Science and Technology
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• v.15 no.5
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• pp.656-664
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• 2001

A theoretical analysis is performed to describe the qualitative behavior of transient buoyant flows in a vertical channel. Consideration is given to the case of a fluid with a pre-existing stratification. The fluid motion is generated by giving impulsive anti-symmetric step-changes in temperature at the vertical left ad right sidewalls. The qualitative character of the flow is shown to be classified in the Rayleigh number (Ra)-Prandtl number ($sigma$) diagram. The transitory approach to the steady state can be monotonic or oscillatory, depending on ($sigma$-1)$^2$$pi$$^4$ 4$sigma$$R_a$. The prominent characteristics of time-dependent flow are discussed for large $R_a$. The profiles of temperature and velocity in the transient phase are depicted, which disclose distinctive time scales of motion. The transient process is shown to be sensitive to the Prandtl number. The detailed evolutions of flow and temperature fields are illustrated for large $R_a$.

• Research in Mathematical Education
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• v.11 no.2
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• pp.87-100
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• 2007

This paper is intended to document the development of the Mathematics across the Curriculum (MAC) movement, following a mathematics problem solving model. Of course, just as new, related problems often arise after we have completed the solution of a current mathematics problem, so too, many questions remain regarding the future of MAC. Although preliminary assessments have been favorable, no broad-based evaluation of the impact of MAC has been conducted. To what extent has the promise of increased student understanding of mathematics and its connections to other disciplines been realized? What can be done to overcome logistical obstacles preventing instructors from working together in real schools settings? Are changes in institutional culture and relationships among academics merely transitory? Is the development of a strong base of curricular materials forthcoming? In other words, will MAC reach a level of educational permanence, or ultimately be discarded as another interesting, but unmanageable instructional fad?