• The Journal of shipping and logistics
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• v.35 no.1
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• pp.93-109
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• 2019

This study applied the statistically significant factors to the short-run model in the existing nonlinear long-run equilibrium relation analysis for the forecasting of maritime economy using the mixed cycle model. The most common univariate AR(1) model and out-of-sample forecasting are compared with the root mean squared forecasting error from the mixed-frequency model, and the prediction power of the mixed-frequency approach is confirmed to be better than the AR(1) model. The empirical results from the analysis suggest that the new approach of high-level mixed frequency model is a useful for forecasting marine industry. It is consistent that the inclusion of more information, such as higher frequency, in the analysis of long-run equilibrium framework is likely to improve the forecasting power of short-run models in multivariate time series analysis.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.5
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• pp.393-400
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• 2011

The mass transport is very complicated at the area which has the macro tide and complex geometry such as Gyeonggi bay. Especially, the long period current has a strong influence on the estuarine ecosystem and the long-term distribution of substances. The long period current is caused by several external forcing, whose unique characteristic varies spatially and temporally. The variation characteristics of long period current is analysed and its generation mechanism is studied. The tidal nonlinear constituents such as overtide and compound tide are generated due to nonlinear interaction and it causes mean sea level setup. The tidal wave propagating up into estuary is transformed rapidly by decrease of cross-sectional area and depth. Therefore the mean sea level is getting rise toward upriver. The high and low tide level is similar between down-river(Incheon) and up-river(Ganghwa) during neap tide when the tidal deformation is decreased. The tidal phase difference between two tidal stations causes a periodic fluctuation of sea level difference. The low water level of Ganghwa station during spring tide does not descend under EL(-)2.5 m, but the low water level of Incheon fall down under EL(-)4.0 m. The variation of tidal range and its sea level are increased during spring tide. It is found that the long period current $M_{sf}$ is quite similar to that of sea level difference between the two tidal stations. It means that the sea surface inclination caused by the spatial difference of tidal deformation is important forcing for the generation of long period current.

• KDI Journal of Economic Policy
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• v.28 no.2
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• pp.51-96
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• 2006

Two conditions should be satisfied if fiscal policy is to stabilize economic cycles; proper policy timing and significant policy effect. This paper evaluates whether the policy timing has been proper in Korea by investigating the correlation between fiscal policy stance and economic conditions. We first calculate quarterly FIs (Fiscal Impulse) using the estimated potential GDP and fiscal balance data. Based on these indices, we 1) analyze how FIs respond to the economic conditions summarized in GDP gap through regression analysis, 2) compare average FIs in expansionary and recessionary periods according to the NSO's economic cycles, 3) evaluate fiscal policy maker's perception of economic conditions and its intention by reviewing the budget proposals. Although regression analysis shows that overall fiscal policy, especially expenditure side, has properly responded to economic conditions, average FIs do not show the significant difference between expansionary and recessionary periods. It is inconclusive whether the fiscal policy timing has been proper. Budget proposals show that actual fiscal policy stance has been sometimes inconsistent with the policy intention, which implies that it is hard to utilize fiscal policy actively to stabilize the economy.

• Journal of Mushroom
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• v.19 no.2
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• pp.96-102
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• 2021

A new cultivar of oak mushroom 'Dadam' was bred from monokaryotic strains of 'GMLE36062-4' and 'GMLE36288-34'. The optimum temperature for mycelial growth of the new cultivar 'Dadam' on potato dextrose agar was 19-22℃. Total cultivation period of the new cultivar, from innoculation to its first harvest, was 135-139 days, similar to that of the control cultivar 'Hwadam'. The pileus color and stipe thickness of the new cultivar were darker and thinner than those of 'Hwadam'. Total yield of 'Dadam' was 621 g per 3 kg substrate, and is higher than that of 'Hwadam' (371 g). In farmhouse field test, it showed that the period of mycelial growth, browning, and fruiting body formation were the same as those of the control cultivar L808. The number of available fruiting bodies of 'Dadam' was 15, and is lower than that of the control (47), therefore, it was possible to save workforce in thinning. The total yield for 2 flush was 480 g for 'Dadam', similar to the 473 g of the control cultivar.

• Venture DIGEST
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• s.101
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• pp.20-21
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• 2006

반도체 생산에 있어서 세계 반도체 업계는 분업화.전문화의 추세에 있다. 최근 들어 제품.기술주기의 축소, 경기변동의 심화, 공급능력 과잉등의 요인으로 세계 메모리 반도체업계의 재편이 이루어지고있는 것이다. 특히 1996년 이래 경기침체를 겪어 온 세계 반도체 업계는 생존 및 국제경쟁력 제고를 위해 다각적으로 인수.합병을 비롯한 전략적 제휴를 추진하고 있다.

• The Korean Journal of Mycology
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• v.50 no.2
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• pp.93-102
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• 2022

A new cultivar of oak mushroom Lentinula edodes 'Jadam' was bred from monokaryotic strains of 'Hwadam-18' and 'GMLE36295-22'. The optimum temperature for mycelial growth of 'Jadam' on potato dextrose agar was 22-25℃. Total cultivation period of the new cultivar, from inoculation to its first harvest, was 122-124 days, shorter to that of the control cultivar 'Hwadam'. Total yield of 'Jadam' was 623.8 g per 3 kg substrate, and is higher than that of 'Hwadam' (455.2 g). In the fruiting body of the new cultivar, the stipe was shorter and thinner than those of 'Hwadam'. A farmhouse field test showed that the period of mycelial growth and browning was shorter than that of control cultivar 'L808'. The total yield for 2 flush was 543.3 g for 'Jadam'. It was similar to the 585.3 g of the control cultivar. Therefore, the new cultivar 'Jadam' could be a substitute for 'L808' in the field of farms.

• 사회경제평론
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• v.29 no.1
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• pp.71-98
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• 2016

This study reveals the followings in the Tugan's business cycle thoery. First, Tugan tried to construct a business cycle theory based on his market theory. But Tugan' theory is lack of logical consistency. Second, Tugan's critics as well as defenders did not understand his theoretical error. Underconsumption theorists did not evaluate Tugan's periodical crisis theory while only criticizing Tugan's crisis theory neglected a consumption. Bauer developed Tugan's periodical crisis by using the reproduction scheme including a hoarded money. Hilferding only constructed a theory of crisis properly criticizing Tugan's crisis theory on the basis of Marx's concept of crisis.

• Journal of Korea Technology Innovation Society
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• v.5 no.2
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• pp.129-140
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• 2002

This study is try to do the empirical tests on the relationship among innovation cycle, investment cycle, and business cycle suggested in recent economic growth models. We apply co-spectra analysis to estimate dynamic correlations in the extraction HP filtered variables and first difference filtered variables in our data set. Our empirical results are; (i) an existing asynchronization between innovation cycle and investment cycle, (ii) in the long frequency, an existing positive correlation between innovation cycle and business cycle, (iii) in the short frequency, however, a finding the high negative correlation between the two cycle. Our empirical findings support the recent growth through cycle models and suggest some economic policy implementations for economic stabilization during a severe business cycle.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.39-42
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• 2002

• Environmental and Resource Economics Review
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• v.29 no.2
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• pp.171-194
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• 2020

We revisit the impact of oil shocks on the Korean economy and examine how this impact varies depending on a business cycle. First, we estimate the probability of a recession through a logistic probability distribution, and correct the probability to match business cycles announced by the Korea National Statistical Office. We set up a STVAR model to analyze the response of macroeconomic variables to oil shocks according to business cycles. We find that oil shocks during the recession have a negative effect on GDP in the mid- and long-term, but during the expansion, GDP does not show a statistically significant response to oil shocks. We presume that this finding is associated with the factors of both the increase in demand for consumption and the increase in current account during the economic boom. Also, we find that the impact of oil shocks on the price level was also observed differently in terms of the persistence of inflation by business cycle. These results highlight the importance of an application of a regime switching model, which has been widely used in energy economics in recent years.