• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.142-147
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• 2008

This paper reports an analysis of self-pressurization in a closed cryogenic liquid storage system and its comparison with experimental data using liquid nitrogen. Partial equilibrium model(PEM), revised thermodynamic analysis of homogeneous model, has been applied for the pressurization in a closed tank. The vapor and liquid bulk temperature and the liquid-vapor interface temperature are separately calculated as their own representative values in this analysis. The analysis results of the partial equilibrium model are compared with the experimental data and other preceding homogeneous temperature models for validation.

• Journal of Biosystems Engineering
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• 제15권1호
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• pp.44-51
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• 1990

Four models in current use for cereal grain drying, equilibrium model, Morey model, partial differential equation model and simplified partial differential equation model, were modified to be suitable for natural air drying of barley. The predicted by the four models and experimental results were compared. Three models except equilibrium model predicted moisture comtent and grain temperature very well. But equilibrium model overpredicted moisture content and grain temperature of bottom layer. The degree of prediction of the four models for relative humidities of exhaust air didn't differ much from one another and equally the four models predicted relative humidity statisfatorily. Morey model took much shorter computing time than any other models. Therefore, considering the degree of prediction and computing time Morey model was the most suitable for natural air drying of barley.

• 재무관리연구
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• 제12권1호
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• pp.145-165
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• 1995

This paper studies a partial coordination situation where a set of countries coordinate their monetary policies among themselves;while the rest of the world choose their policies independently. Using a three-country orewlapping generations model, it is shown that nash partial-coordination equilibrium does not exist. This paper also studies the partial coordination under unanticipated productivity shocks.

• 지역연구
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• 제13권2호
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• pp.45-54
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• 1997

A regional economy is characterized as a spatial economy. However the literature shows that it has been treated as a point economy since space is little recognized in regional modeling due to mathematical complication. This leads to the fact that regional model does not sufficiently represent regional characteristic. This paper attempts to construct a regional growth model in a partial equilibrium framework specifically taking into consideration land as a primary factor. The model is formulated largely neoclassical. Labor is assumed to move in response to differences in the wage rate, while capital is perfectly mobile across regions. The paper shows that two growth equilibrium points exist, one stable equilibrium point and the other unstable equilibrium point. The unstable growth equilibrium indicates the existence of minimum threshold that a region must overcome the minimum threshold to grow constantly. Consequently, directions of regional growth are characterized by two growth paths depending on the initial condition of a region. That is to say, a region below the minimum threshold is converging toward the lower stable equilibrium point over time. When a regional economy initially lies above the minimum threshold, it will grow forever. A regional economy is not thus necessarily converging a stationary is not thus necessarily converging a stationary equilibrium point through factor movement. Finally, the impacts of the presence of agglomeration economies and diseconomies are analyzed through the phase diagram. The paper also shows that agglomeration economies result in lowering the minimum threshold and in escalating the level of stable equilibrium However, when agglomeration diseconomies prevail, the results are opposite, i.e., rising the minimum threshold of growth and lowering the growth level of stable equilibrium.

• 한국산림과학회지
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• 제97권4호
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• pp.458-466
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• 2008

본 연구는 장기 밤수급 예측과 국내외 시장여건 변화가 국내 밤시장에 미치는 영향을 분석하기 위하여 수행되었다. 이를 위해 본 연구에서는 생밤시장과 깐밤시장을 상호 수직적으로 연결하는 부분균형모델을 개발하였다. 개발된 모델의 내생변수에 대한 예측능력을 측정하기 위하여 1990년부터 2003년까지 사후예측을 실시하였다. 전반적으로 신규재배면적 및 폐기면적을 제외하고는 모든 내생변수들에 대한 모델의 예측오차가 낮았다. 수급예측 결과 국내 생밤생산량은 2005년에 76,447톤에서 2020년에는 76,286톤으로 약간 감소할 것으로 예측되었으며, 일본으로 수출되는 깐밤의 양은 지속적으로 감소할 것으로 예측되었다.

• 수산경영론집
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• 제43권2호
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• pp.1-14
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• 2012

The main purpose of this study is to analyze the effect of Korea-China free trade agreement(FTA) on Korea's fisheries trade using the partial equilibrium analysis model of Feenstra(1995). The study tries to show the impact on trade flows and welfare of the elimination of tariffs Korea-China FTA on Korea's fisheries sector among several scenarios of trade liberalization. The results of the study indicate that the increase of fisheries export to China is lower than that of fisheries import from China. Therefore Korea-China FTA results in the decrease of domestic of fisheries production even though total welfare effect is positive. The study suggest several policy proposals for soft-landing of Korea-China FTA on Korea's fisheries sector. One of them is to lengthen the term of tariff elimination to minimize the impact on domestic fisheries sectors.

• 농업과학연구
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• 제48권4호
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• pp.815-829
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• 2021

The purpose of this study is to construct a flatfish outlook model that is consistent with the "Fisheries outlook" monthly publication of the fisheries outlook center of the Korea Maritime Institute (KMI). In particular, it was designed as a partial equilibrium model limited to flatfish items, but a model was constructed with a dynamic ecological equation model (DEEM) system, considering biological breeding and shipping times. Due to limited amounts of monthly data, the market equilibrium price was calculated using a recursive model method as the inverse demand. The main research results and implications are as follows. As a result of estimating young fish inventory levels, the coefficient of the young fish inventory in the previous period was estimated to be 0.03, which was not statistically significant. Because there is distinct seasonality, when estimating the breeding outcomes, the elasticity of breeding in the previous period was found to exceed 0.7, and it increased more as the weight of the fish increased, in addition, the shipment coefficient gradually increased as the weight increased, which means that as the fish weight increased, the shipment compared to the breeding volume increased. When estimating shipments, the elasticity of breeding in previous period was estimated to respond elastically as the weight increases. The price flexibility coefficient of the total supply was inelastically estimated to be -0.19. Finally, according to a model predictive power test, the Theil U1 was estimated to be very low for all of the predictors, indicating excellent predictive power.

• 수산경영론집
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• 제47권4호
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• pp.65-75
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• 2016

The purpose of this study was to analyze the production and marketing control effects of aqua-cultured flounder required for stable income growth of aqua-cultured household. We analyzed the supply and demand structure of cultured flounder using the partial equilibrium model approach. And we estimated the optimal yield of cultured flounder and analyzed the effect of marketing control through constructed model. The main results of this study are summarized as follows. First, the fitness and predictive power of the estimated model showed that the RMSPE and MAPE values were less than 5% and Theil's inequality coefficient was very close to 0 rather than 1. It was evaluated that the prediction ability of the aqua-cultured flounder supply and demand model by dynamic simulation was excellent. Second, dynamic simulation based on policy simulation was conducted to analyze the price increase effect of production and shipment control of cultured flounder. As a result, if the annual production volume is reduced by 1%, 5%, and 10% among 32,852~37,520 tons, it is analyzed that the price increase effect is from 1.2% to 12.5%. Finally, this study suggests that the production and marketing control can increase the price of aqua-cultured flounder in the market. In this paper, we propose a policy implementation of the total supply system instead of conclusions.

• 한국산학기술학회논문지
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• 제19권7호
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• pp.415-422
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• 2018

Lycorma delicatula는 꽃매미로 알려져 있으며, 베트남, 인도, 남중국과 같은 동남아시아의 토착 해충이다. 꽃매미는 한국에 유입되어 최근 몇 년간 급속히 퍼져 특히 과일 나무에 피해를 입히고 있다. 본 연구의 목적은 Lycorma delicatula의 사례를 이용하여 미발생 병해충 영향 분석을 위한 연구방법과 추정 결과를 제시하는 것이다. 본 연구에서는 Lycorma delicatula 발생으로 인한 농가의 직접소득감소를 측정하기 위해 부분예산(partial budget) 방법을 사용하였고, 해충 발생으로 인한 사회후생 변화를 조사하기 위해 부분균형(partial equilibrium) 모형을 사용하였다. 또한 병해충 발생 적합도를 고려한 다양한 기후 시나리오 하에서 Lycorma delicatula 발생 위험이 농가소득에 미치는 영향을 추정하였다. 기후변화가 지속됨에 따라 국내 생태계는 점점 돌발 외래 병해충에 취약해질 것으로 예상되며, 이에 따른 경제적 피해는 더욱 증가할 것으로 전망된다. 나아가 이 연구는 향후 국가 해충 방제 및 검역 시스템의 효율성 평가의 기반이 될 수 있을 것으로 기대된다.

• Korean Journal of Mathematics
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• 제31권1호
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• pp.17-23
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• 2023

For a locus with two alleles (I^A and I^B), the frequencies of the alleles are represented by $$p=f(I^A)={\frac{2N_{AA}+N_{AB}}{2N}},\;q=f(I^B)={\frac{2N_{BB}+N_{AB}}{2N}}$$ where N_AA, N_AB and N_BB are the numbers of I^AI^A, I^AI^B and I^BI^B respectively and N is the total number of populations. The frequencies of the genotypes expected are calculated by using p², 2pq and q². Choi defined the density and operator for the value of the frequency of one gene and found the adapted partial differential equation as a follow-up for the frequency of alleles and applied this adapted partial differential equation to several diploid model [1]. In this paper, we find adapted equations for the model for selection against recessive homozygotes and in case that the alley frequency changes after one generation of selection when there is no dominance. Also we consider the triploid model with three alleles I^A, I^B and i and determine whether six genotypes observed are in Hardy-Weinburg for equilibrium.