• Korean Journal of Labor Studies
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• v.14 no.2
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• pp.59-93
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• 2008

본 논문은 한국고용정보원의 '대졸자 직업이동경로조사(2007)' 자료를 활용하여 청년 고학력자의 성별 노동시장 차별이 존재하는지를 확인하고자 하였다. 청년 고학력층은 경력단절, 육아와 가사부담에 따른 노동시장 차별을 비교적 덜 받을 것으로 예상된다는 점에서 이들 집단에서의 차별 존재는 최근 노동시장 문제를 파악하는 데 있어 매우 중요한 의미가 있다. 우리는 성별 노동시장 차별을 분석하기 위해서 차별에 관한 실증분석 방법으로 일반적으로 많이 사용되는 오하카 요인분해 모형을 활용하였다. 특히 고용차별을 확인하기 위해서 이항선택 모형에 적용한 요인분해 분석방법을 활용하였다. 전반적인 결론은 청년층 고학력자 여성들도 청년층 고학력자 남성에 비해 고용 및 임금차별을 경험한다는 것이다. 특히 본 연구에서는 성별 임금차별 뿐만 아니라 비정규고용 및 비공식고용과 같은 고용형태상의 차별도 확인할 수 있었다. 연령, 4년제졸 여부, 결혼여부가 성별 고용 및 임금격차를 초래하는 주요 요인으로 분석되었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1D
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• pp.45-55
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• 2008

The objective of this research was to develop a VEPCD (ViscoElastoPlastic Continuum Damage) Model which is used to predict the behavior of asphalt concrete under various loading and temperature conditions. This paper presents the VEPCD model formulated in a tension mode and its validation using four hot mix asphalt (HMA) mixtures: dense-graded HMA, SBS, CR-TB, and Terpolymer. Modelling approaches consist of two components: the ViscoElastic Continuum Damage (VECD) mechanics and the ViscoPlastic (VP) theory. The VECD model was to describe the time-dependent behavior of HMA with growing damage. The irrecoverable (whether time-dependent or independent) strain has been described by the VP model. Based on the strain decomposition principle, these two models are integrated to form the VEPCD model. For validating the VEPCD model, two types of laboratory tests were performed: 1) a constant crosshead strain rate tension test, 2) a fatigue test with randomly selected load levels and frequencies.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.211-219
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• 2015

Generalized linear mixed models are used to analyze longitudinal categorical data. Random effects specify the serial dependence of repeated outcomes in these models; however, the estimation of a random effects covariance matrix is challenging because of many parameters in the matrix and the estimated covariance matrix should satisfy positive definiteness. Several approaches to model the random effects covariance matrix are proposed to overcome these restrictions: modified Cholesky decomposition, moving average Cholesky decomposition, and partial autocorrelation approaches. We review several approaches and present potential future work.

• The Korean Journal of Financial Studies
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• v.12 no.1
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• pp.183-213
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• 2006

본 연구의 목적은 공적분 검정과 예측오차 분산분해 방법을 이용하여 우리나라 주식시장에서 주가지수와 거시경제 변수들과의 계량적 관계를 파악하고 종합주가지수와 밀접한 관련성이 있는 변수를 사용하여 종합주가지수와 거시경제변수들 사이의 모형을 추정하는 것이다. Johansen 공적분 검증을 이용한 결과를 보면 종합주가지수와 7개의 거시경제변수들(총통화, 소비자물가지수, 금리, 산업생산지수, 원 달러 환율, 국제원유가격, 경상수지) 사이에 상당히 밀접한 연관성이 있으며, 이들 변수들 사이에 장기적 균형 관계가 존재하였다. 예측오차 분산분해 방법을 사용한 분석결과에서는 종합주가지수의 분산을 예측하는데 있어서 이들 거시경제변수들의 설명력이 매우 높게 나타났다. 또한 우리나라의 주식시장에서는 금리, 국제원유가격, 경상수지 등의 요인보다는 원 달러 환율, 소비자물가지수, 산업생산의 비중이 더 크다는 사실을 알 수 있었다. 우리나라의 자본시장에서는 1997년 말 외환위기를 전후로 하여 현저한 구조적 변화가 존재하였기 때문에 백터오차수정모형을 설정할 때에는 외환위기 이전기간과 이후기간으로 나누어서 분석하는 것이 더욱 타당함을 확인할 수 있었다.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.345-352
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• 2018

In this study, rainfall data with various temporal scales (3-, 6-, 12-, 24-hr) are disaggregated into 1-hourly rainfall data to evaluate the performance of rainfall disaggregation technique. The rainfall disaggregation technique is based on a database generated by the stochastic point rainfall model, the Neyman-Scott Rectangular Pulse Model (NSRPM). Performance evaluation is carried out using July rainfall data of Ulsan, Changwon, Busan and Milyang weather stations in Korea. As a result, the rainfall disaggregation technique showed excellent performance that can consider not only the major statistics of rainfall but also the spatial correlation. It also indirectly shows the uncertainty of future climate change scenarios with daily temporal scale. The rainfall disaggregation technique is expected to disaggregate the future climate change scenarios, and to be effective in the future watershed management.

• Geophysics and Geophysical Exploration
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• v.5 no.2
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• pp.78-83
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• 2002

The finite element method combined with the sensitivity method is adopted for 2-dimensionl Fourier transform inversion. To improve the efficiency of inversion calculation, multi-resolution wavelet method is proposed., Theoretical data which is obtained from above method is shown to examine the proposed method. Theoretical model assumes that underground cavity is located in limestone area. In theoretical model, 16 current and potential electrodes are located to get theoretical data. It is shown that the about inversion method is very exact and useful calculation method, in case the larger model is very small such as under ground cavity.

• Journal of Labour Economics
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• v.41 no.3
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• pp.61-93
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• 2018

This paper examines the gender pay gap among doctorate holders in Korea to understand the determinants of this gap and control of its variation. A particular focus of this study is to seek to infer the extent to which this pay gap is the consequence of gender-based disparate treatment. The main results indicate that there is a sizeable gender pay gap even among workers with doctorate degrees, that is, very highly educated workers. Moreover, this gender pay gap cannot be largely explained by gender differences in characteristics, indicating the existence of discrimination against female doctorate holders in the Korean labor market.

• Management & Information Systems Review
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• v.28 no.3
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• pp.69-98
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• 2009

This study investigates in-sample and out-of-sample predictive abilities of accruals and accruals components with respect to future cash flows using models developed by Barth et al.(2001). In tests, data collected fromda62 Korean KOSPI and KOSDAQ listed firms for ccr4-2007 are used. Results of in-sample prediction tests are similar with those of Barth et al.(2001). Their accrual components model is better than other three models(NI only model, CF only model and NI-total accruals model) in future cash flows predictive ability. That is, in the case of in-sample prediction, accrual components excluding amortization have additional information contents for future cash flows. But in out-of-sample tests, the results are different. The model including operational cash flows(CF only model) shows best out-of-sample predictive ability with respect to future cash flows among above four prediction models. The accrual components model of Barth et al.(2001) has worst out-of-sample predictive ability. The results are robust to sensitivity analyses. In conclusion, we can't find the evidence that accruals and accrual components have predictive ability with respect to future cash flows in out-of-sample prediction tests. This results are consistent with results of Lev et al.(2005), and inconsistent with the belief of accounting standards formulating organizations such as FASB and KASB.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.266-268
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• 2004

대부분의 유기물은 토양의 특성에 따라 그 흡착 및 탈착 양상이 다르며 이는 오염물질의 토양에서의 지속성 및 이동성에 영향을 미치게 된다. 본 연구에서는 대표적인 유기오염물인 PAH(Polycyclic Aromatic Hydrocarbon)에 대하여 흡착 및 탈착과 오염물질의 미생물 분해 등을 통한 제거 기작과의 연관성을 연구하고자 한다. PAH의 이론적인 미생물분해반응식은 열역학적 이론을 바탕으로 하는 반쪽반응방법을 사용하여 예측할 수 있다. 오염물과 토양의 특성에 따른 흡착 및 탈착 양상을 파악하고, 앞에서 구한 미생물 분해반응식을 이용하여 이론적 분해량을 예측하면 오염물의 생물학적 이용성과 노출량을 결정할 수 있다 이를 위하여 본 연구에서는 토양의 여러 특성을 분석한 후, PAH의 미생물 분해량 및 분해율을 측정하고자 한다. 실험을 통하여 실제 토양에서 측정된 PAH 분해량과 위의 이론적 분해량 예측 결과 사이의 관계를 토양의 특성을 이용하여 설명할 수 있으며 나아가 오염물질의 생물학적이용성에 관하여 개략적으로 일반화된 예측 모형을 얻을 수 있을 것이다. 본 연구를 통하여 토양과 유기오염물질, 미생물간의 상호 작용에 대한 이해를 높이고 보다 실질적인 유기오염물의 생물학적 이용성을 예측할 수 있는 방안을 마련할 수 있을 것이다.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.294-299
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• 1992

This study was to examine the effect of functional properties of soy protein isolate(SPI) and qualities of soybean curd upon proteolytic hydrolysis. SPI was hydrolyzed using proteolytic enzyme, bromelain. The protein content of SPI by microkjeldahl method was 84% and the degree of hydrolysis in modified soy protein isolate(MSPI) was 2.7%. The solubility of MSPI was higher than that of control at various pH tested and proteolytic hydrolysis was increased emulsion formation and foam expansion while decreased emulsion stability, foam stability and calcium precipitation. Modified soybean curdI, standard soybean milk: Modified soybean milk=3:1, was soft and springy soybean curd when the texture properties of soybean curd were tested by texture profile analysis using Instron and sensory evaluation. The rheological model of soybean curds was investigated by stress relaxation test. The analysis of relaxation curve revealed that the rheological behavior of soybean curds could be expressed by 7-element generalized Maxwell model. The equilibrium modulus and modulus of elasticity decreased as the ratio of modified soybean milk was increased.