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

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.10
• /
• pp.589-601
• /
• 2020

The Construction Standard Unit Price (CSUP) sets the standard for calculating the estimated construction cost. The CSUP is used as basic data for preparing a standard price for public construction. Currently, the CSUP is calculated in consideration of the market and construction field conditions. However, a long-term management plan was established to prepare revised standards. As part of the plan, a field survey was conducted on changes in construction conditions and market prices. However, the plan continued for more than 5 years. Thus, the plan has a problem of difficulty continuously managing primary activities that have high importance and high price volatility. Therefore, to efficiently manage the CSUP, this study identifies the primary activities of the CSUP and presents a management plan. Through importance analysis and unit price volatility analysis, 242 primary activities in 35 activity groups were identified. Also, a management plan is presented based on the importance levels of activities. The primary activities and management plan could enable the timely revision of important activities. The results of this study provide a base for reflecting the appropriateness of construction cost criteria on time.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.101-101
• /
• 2015

1986년 한강종합개발사업으로 대규모 준설이 실시되고, 수위가 낮아지면서 발생한 문제점을 해결하고자, 1988년 김포대교 직하류 지점에 신곡수중보를 건설하였다. 당시 수중보의 설치목적은 취수시설 유지를 위한 수위유지가 주요기능이었으나, 30년이 지난 지금 생활용수 취수시설은 잠실 수중보 상류로 모두 이전하였고, 농업용수와 일부 공업용수 등의 일부 시설만이 남아 있어 신곡수중보 시설의 필요성 및 현재 기능에 대한 재평가가 필요한 시점이다. 신곡수중보 철거시 변화하는 한강 본류의 수위를 모의하기 위해 수리학적 모형인 HEC-RAS를 이용한 부정류 모의를 실시하였다. 모형의 보정을 위해 저수기를 대표하는 2014년 4월부터 5월까지 45일간과 풍수기를 대표하는 2014년 8월부터 9월까지 45일간을 모의하였다. 조위영향을 받고 있는 강화대교 관측수위를 기점수위로 선정하고, 팔당댐 유량을 유량조건으로 모의하였으며, 본류구간의 전류, 행주대교, 한강대교 지점의 실측수위와 모의결과는 잘 일치하는 것으로 나타났다. 신곡수중보 철거시 평가를 위해 팔당댐 방류량이 최소가 되는 조건과 한강의 갈수량, 저수량, 계획홍수량 등 유량조건 변화에 따른 한강 본류수위를 비교하였다. 보 철거시 서해안의 조위영향이 잠실수중보 직하류지점까지 영향을 미치고, 일시적인 수위하강 현상이 발생하는 것으로 모의되었다. 보 철거에 의해 감조하천으로 변화되는 구간에서는 전반적인 유속이 증가하여, 현재 문제가 되고 있는 신곡수중보 직상류 및 지천 합류부 주변의 퇴적문제와 수질 문제개선에 도움을 줄 것으로 예상된다. 또한 신곡수중보 상류지역에서 잠실수중보 하류까지 발생하는 수위변화와 수면폭변화는 간조대 형성에 유리한 조건을 제공하여 한강변의 퇴적지 면적 증가 및 생태계 서식처 제공에 도움을 줄 것으로 기대된다. 다만 신곡수중보 하류지역의 수위는 현재보다 전반적인 상승이 예상되어 장항습지 면적이 일부 감소할 것으로 예상되지만, 홍수시 침식 및 퇴적이 가장 활발히 발생하므로 하상변동 등에 대한 면밀한 평가가 필요하다. 또한 홍수기 신곡수중보 구조물에 대한 평가 결과에서는 철거 시 한강 본류의 하천 수위가 일부 하강하는 것으로 모의되어 하천을 횡단하는 구조물이 홍수위 상승에 기여한다고 판단되므로 대안마련을 위한 종합적인 평가가 필요하다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.91-91
• /
• 2019

아열대 해양성 기후로 변화하고 있는 다우지역인 제주도는 각종개발 등 도시화로 인한 불투수층 증가가 급증하고 있으며 기후 변동에 의한 강우량은 더욱 늘어 홍수 피해가 빈번히 발생하고 있어 저영향개발기법(LID, Low Impact Development)을 통한 빗물을 지하로 침투시켜 지하수 보호 및 확보와 동시에 재해 저감을 할 수 있는 기술개발이 시급한 실정이다. 현재 설치된 재해저감방식 중 침투트렌치에 의한 침투방식은 제주도의 보전자원인 화산석인 현무암을 주 재료로 하고 있어 2차환경 파괴를 야기 시키고 있지만 암을 보전하고 대처할 수 있는 신재료와 신기술 관련 침투방식의 성능 극대화에 대한 연구가 미진하며, 지하수를 주 수원으로 하고 있는 제주도에서 초기 강우 배제 없이 침투시킬 경우 지하수 오염 가능성도 상존하고 있다. 본 연구는 지하수의 제주형 인공함양정과 재해영향평가 지침에서 제시한 암을 충진하는 정형화된 침투식 방법을 개선하여 초기 강우의 수질오염을 억제하면서 지하수 인공함양과 재해저감을 위해 침투와 저류를 동시에 할 수 있는 신기술을 상용화와 침투형 저류지의 설치 초기비용 및 유지비용을 절감하고 부지확보에 따른 사업자의 부담을 경감 할 수 있는 침투트렌치 형식의 침투저류시스템을 개발하여 실용화하는데 있다. 이에 따라 본 연구에서는 제주도인 경우 일시적 높은 첨두유량으로 인해 지표유실 및 침수범람이 빈번하게 발생하고 도시화에 따른 포장면적 증가로 지표수 유실이 증대 되는 점을 감안하여 이를 저감하기 위한 첨두유량의 해결방안으로 저류용 침투저류조 내 유입수의 신속한 침투기능과 지하수 함양 증대에 기여 등 제주형 집중호우 대비 침투저류조 설치에 따른 효과 및 적용 가능성을 조사하였다.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.13 no.3
• /
• pp.3-9
• /
• 2009

Purpose: It is well-known that stress-induced stunning and reversible perfusion defect have impact on ejection fraction (EF) when performing myocardial perfusion SPECT. Due to these reasons, gated SPECT is recommended at stress and rest studies. And there was many experiments to analyze between Stress and Rest EF by using $^{99m}Tc$-MIBI. The aim of this study is to analyze between stress EF and rest EF at myocardial perfusion SPECT by using $^{201}Tl$ and define possible predictors of EF variability. Materials and Methods: From 2008 June to 2009 February, we analyzed 144 patients undergoing $^{201}Tl$ gated myocardial perfusion SPECT in ASAN medical center. To analyze the data, we use QGS (Quantitative gated SPECT) software, and derived End-systolic volume (ESV), End-diastolic volume (EDV), EF from the result. In this study, we comparatively analyzed stress/rest EF correlation based on stress/rest EF, EDV, ESV and reversibility of myocardial perfusion defect by using paired t-test, Bland-Altman analysis. Results: Mached pairs of stress EF and rest EF demonstrated excellent correlation (r=0.92) with no statistically significant difference (p=0.11). Bland-Altman analysis demonstrated a mean ${\Delta}EF$ was 0.52% (95% confidential interval[CI], -1.17~0.12%). No statistically significant difference between a mean ${\Delta}EF$ and hypothetic mean of 0 (${\Delta}EF$=0) (p=0.10). In the correlation of ${\Delta}EF$ according to stress/rest EDV and ESV, except rest ESV of <28mL (p<0.05), there was no statistically significant difference. In the correlation of ${\Delta}EF$ according to reversibility of perfusion defect, patients with reversible perfusion defect has statistically significant difference of ${\Delta}EF$ (p<0.05). ${\Delta}EF$ of stress/rest EF showed no statistically significant difference except 55% of rest EF (p<0.05). Conclusion: Like studies with $^{99m}Tc$-MIBI, there was generally no statistically significant difference between stress and rest EF in this study results. However a stress EF of <55%, a rest ESV of <28mL and patients with reversible perfusion defect showed statistically significant difference in ${\Delta}EF$. If performing $^{201}T$ myocardial perfusion SPECT to patients with abnormal cardiac function or reversible perfusion defect, consider this study results and apply it. We expect this study results could be useful predictors of ${\Delta}EF$ variability.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.05b
• /
• pp.548-552
• /
• 2005

새만금호의 완공이후 내부 개발이 완료된 시점에서 만경강 및 동진강 홍수량 유입이 담수호의 수위 및 유속등 수리특성에 어떠한 변화를 가져올 것인가를 평가하기 위한 수치실험이 내부 관리수위(DL=-0.5m, DL=-1.0m, DL=-1.5m)별로 실시되었다. 홍수파의 전파에 따른 동적거동을 이상적으로 모의하기 위해서 본 연구에서는 2차원 수심적분의 모형인 ADCIRC 모형을 새만금 하구호에 적용하였다. 상류의 유입 경계조건으로는 50년 빈도의 홍수수문곡선도를 사용하여 만경강과 동진강의 유입량이 30분 간격으로 변화되는 홍수량을 이용하였다. 하류의 경계조건으로는 신시 수문이 외해의 조위와 내부 관리수위와 연동되어 외조위가 낮아질 때만 수문이 열리는 조건을 설정하는 동적인 경계조건이 설정되었다. 홍수 계산은 4일에 걸쳐 실시되어 새만금호 내부에서 수위와 유속의 변화를 관찰하였다. 만경수계내 홍수파의 동적 거동은 시간이 경과함에 따라 홍수파가 하류로 전파되어 수위와 유속 변화가 크게 나타난다. 만경강 유입부에서는 홍수수문곡선의 시간적 변화가 민감하게 작용하는 반면, 홍수파 전파가 하류로 진행하면서 유입부에서 높아졌던 수위가 새만금호 내부에서는 점차 낮아지면서 안정화 되는 것을 보여주고 있다. 그러나 수문이 위치한 지점에서는 유입 홍수에 의한 영향은 거의 나타나지 않고, 신시수문의 개방에 따라 동적으로 변동되는 것이 지배적이다. 유속 모의 결과 상류 수로부에서는 $1.8m/s\~0.5m/s$로 나타나지만 새만금호에 진입하면서 $0.5m/s\~0.2m/s$의 낮은 유속으로 변한다. 신시 갑문 인근에서는 수문을 닫을 때 일시적인 충격파가 내부로 전파되면서 와동현상을 보이는 등 유속과 수위 변화에 있어 동적으로 복잡한 거동을 보이는 것으로 해석 된다.한 영향을 미치는 인자에 대한 이론적인 분석을 수행하고, 배수갑문 개방에 의한 수질개선효과를 최대화하기 위한 환경관리 방안 제시에 중점을 두어 수행하였다.ncy), 환경성(environmental feasibility) 등을 정성적으로(qualitatively) 파악하여 실현가능한 대안을 선정하였다. 이렇게 선정된 대안들은 중유역별로 검토하여 효과가 있을 것으로 판단되는 대안들을 제시하는 예비타당성(Prefeasibility) 계획을 수립하였다. 이렇게 제시된 계획은 향후 과학적인 분석(세부평가방법)을 통해 대안을 평가하고 구체적인 타당성(feasibility) 계획을 수립하는데 토대가 될 것이다.{0.11R(mm)}(r^2=0.69)$로 나타났다. 이는 토양의 투수특성에 따라 강우량 증가에 비례하여 점증하는 침투수와 구분되는 현상이었다. 경사와 토양이 같은 조건에서 나지의 경우 역시 $Ro_{B10}(mm)=20.3e^{0.08R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식

• KDI Journal of Economic Policy
• /
• v.32 no.3
• /
• pp.1-32
• /
• 2010

The global financial crisis has exerted enormous impacts on the attainment of inflation target in Korea. The annual average CPI inflation was 3.3% during the targeting period of 2007-2009 and the target was $3.0{\pm}0.5%$. Thus Korea has succeeded in keeping annual average CPI inflation just below the upper limit of the 2007-2009 target under the global crisis. This paper intends to evaluate the performance of the inflation targeting system in Korea. First, it estimates the conventional call rate reaction equation under the global crisis and finds that the policy interest rates never reacted to expected inflation, output gap, and won/dollar exchange rate, as expected by theory. Second, it identifies the shock of global financial crisis into core and non-core, applying the structural VAR model. The core shock was defined to have no (medium- to) long-run impact on real output. The core shock was identified to have the character of the demand shock, since it has the positive impact on the inflation and output in the short run. The structural core inflation due to core shock was an attractor of headline inflation, not vice versa. Therefore, the structural core inflation that reflects the demand-side shock would be the better intermediate target for the final headline inflation target than the official core inflation that excludes the volatile inflation of agricultural and oil-related products. During the inflation targeting period of 2007-2009, the structural core inflation was more volatile than the official core inflation, because the global crisis has very large negative impacts on the domestic demand as well as the prices of agricultural and oil-related products. This paper shows that the negative core shock during the fourth quarter of 2008 was larger than that in the financial crisis in 1998. But the core shock turned into positive very quickly in 2009, as the Korean economy recovered very quickly from crisis. The volatile changes in structural core inflation suggests that the Bank of Korea barely managed to attain the 2007-2009 inflation target, owing to the very large negative impacts of the global financial crisis on the domestic demand. It also suggests that the rapid rise in core inflation with the rapid recovery of the Korean economy will lead to rapid rise in headline inflation.

• Clinical and Experimental Pediatrics
• /
• v.45 no.4
• /
• pp.505-511
• /
• 2002

Purpose : Mean platelet volume(MPV) and platelet distribution width(PDW) are useful parameters in evaluating disorders of platelets. In cases with idiopathic thrombocytopenic purpura(ITP), they change as platelet count increases. In this study, we compared the values of MPV and PDW in ITP patients at diagnosis with those of normal children. We also studied whether the early changes in MPV may predict the clinical course. Methods : From December 1995 to May 2001, 71 patients with ITP were admitted to Ajou University Hospital. They were treated with IVIg 400 mg/kg for five days and MPV, PDW, platelet count were analysed. Normal control group(n=38) was compared. The study group was divided into acute and chronic forms, and also divided into group A, good early responders whose platelets increased more than $100,000/{\mu}L$ within 5 days and group B who did not. Results : Mean value of MPV at diagnosis in ITP patients was lower than the normal control group(P<0.05). In group A, MPV was abruptly increased on the first day after IVIg and then started to decrease. But in group B, MPV was steadily increased until the fourth day after IVIg. In the normal control group, there were inverse correlations between platelet count and MPV(r=-0.415, P<0.05), but in ITP patients, there were positive relationships between platelet count and MPV(r=0.646, P<0.05) at diagnosis. Conclusions : MPV at diagnosis of ITP was lower than the normal control. MPV and PDW could not predict the course of ITP patients, but MPV could distinguish good early responders. More research is needed to find out the reasons of decreased MPV at diagnosis of ITP.

• Clinical and Experimental Pediatrics
• /
• v.48 no.11
• /
• pp.1187-1192
• /
• 2005

Purpose : The purpose of this study is to determine the effectiveness of intravenous immunoglobuin (IVIG) administration in fullterm neonates having clinically suspected neonatal sepsis. Methods : Forty full-term neonates admitted to the neonatal intensive care unit with clinically suspected neonatal sepsis, who had at least two positive diagnostic criteria were enrolled. Twenty neonates were enrolled into the IVIG arm and 20 in the placebo arm. Neonates with a gestational age of less than 36 weeks and those with any major congenital malformation were excluded. The neonates were randomized to receive 1 g/kg of IVIG or equivalent amount of normal saline. The treatments including antibiotics and supportive care were administered. Results : The neonates in the therapy and placebo groups were comparable in terms of birth weight, gestational age, sex distribution, duration of antibiotics therapy and admission, elevation of serum IgG level, mortality rate, change of CBC, and serum level of acute phase reactants etc. Conclusion : Serum IgG values increased significantly 5 days after administration of IVIG in the IVIG-treated group and decreased significantly 5 days after administration of normal saline in the placebo group. However, there was no significant difference in the duration of antibiotics therapy and admission, or of mortality between the IVIG-treated and placebo groups. No adverse reactions to the IVIG infusions were noted during the study. Our preliminary observations suggest that the administration of 1 g/kg IVIG to neonates had some effect on augmentation of humural immune status in neonates with clinically suspected sepsis. But further study is needed to verify the benefit of IVIG infusion to neonatal sepsis.

• Management & Information Systems Review
• /
• v.35 no.4
• /
• pp.169-184
• /
• 2016

Deferred tax assets (liability) in a company's financial statements are to reflect the temporary difference between taxable income and accounting income and therefore can provide useful information as a proxy for discretionary accruals. In addition, deferred tax assets allow a company to manage its earnings by reviewing the feasibility of the assets' recognition. As such, this study focused on deferred tax assets to examine their relationship with discretionary accruals, which were measured by a modified Jones model (Dechow et al. 1995), and investigated the impact of audit quality on this relationship. In order to control for the effects of tax rate change and measurement credibility, deferred tax assets of 2,670 non-financial firms from 2009 to 2010 were collected as samples for the study. The results of the empirical analysis are as follows. First, the samples as a whole indicated that deferred tax assets have a negative relationship with discretionary accruals in a general sense, but a high-quality audit did not reveal a significant relationship between them. Second, the 1,379 samples with negative discretionary accruals did not reveal a significant relationship between deferred tax assets and discretionary accruals; however, the result showed a significant negative relationship under a high-quality audit. These findings suggest that in the case of negative discretionary accruals, a high-quality audit restricts an earnings management technique that utilizes deferred tax assets and that the assets can be a useful tool for detecting discretionary accruals. The present study is meaningful in that, unlike previous research, it combined the two contrasting roles of deferred tax assets-that of an earnings management detector and an earnings management tool-to examine their general relationship. The study also suggested that audit quality could influence the usefulness of deferred tax assets in providing information on discretionary accruals.