• 수산경영론집
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• 제51권2호
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• pp.51-69
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• 2020

The purpose of this study is to construct an outlook model that is consistent with the "Fisheries Outlook" monthly published by the Fisheries Outlook Center of the Korea Maritime Institute(KMI). In particular, it was designed as a partial equilibrium model limited to abalone items, but a model was constructed with a dynamic ecological equation model(DEEM) system taking into account biological breeding and shipping time. The results of this study are significant in that they can be used as basic data for model development of various items in the future. In this study, due to the limitation of monthly data, the market equilibrium price was calculated by using the recursive model construction method to be calculated directly as an inverse demand. A model was built in the form of a structural equation model that can explain economic causality rather than a conventional time series analysis model. The research results and implications are as follows. As a result of the estimation of the amount of young seashells planting, it was estimated that the coefficient of the amount of young seashells planting from the previous year was estimated to be 0.82 so that there was no significant difference in the amount of young seashells planting this year and last year. It is also meant to be nurtured for a long time after aquaculture license and limited aquaculture area(edge style) and implantation. The economic factor, the coefficient of price from last year was estimated at 0.47. In the case of breeding quantity, it was estimated that the longer the breeding period, the larger the coefficient of breeding quantity in the previous period. It was analyzed that the impact of shipments on the breeding volume increased. In the case of shipments, the coefficient of production price was estimated unelastically. As the period of rearing increased, the estimation coefficient decreased. Such result indicates that the expected price, which is an economic factor variable and that had less influence on the intention to shipments. In addition, the elasticity of the breeding quantity was estimated more unelastically as the breeding period increased. This is also correlated with the relative coefficient size of the expected price. The abalone supply and demand forecast model developed in this study is significant in that it reduces the prediction error than the existing model using the ecological equation modeling system and the economic causal model. However, there are limitations in establishing a system of simultaneous equations that can be linked to production and consumption between industries and items. This is left as a future research project.

• 한국산림과학회지
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• 제103권3호
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• pp.462-472
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• 2014

이 연구는 목제품의 수급모형을 개발하고, 제품별로 중장기적인 수요와 공급을 전망하는 데 목적이 있다. 목제품 시장 수급모형은 주요 제품인 제재목, 합판, 파티클보드, 섬유판, 펄프 등으로 한정하였다. 각각의 제품에 대해 공급함수, 수입수요함수, 수요함수 등을 추정하여 부분균형 모형을 구축하였다. 주어진 외생변수를 이용하여 2050년까지 전망한 결과 제재목, 합판, 섬유판 등의 국내공급 및 수입은 감소할 것으로 예상된다. 이는 환경보호와 자원의 무기화 등으로 인해 국내외 원목가격이 인상될 것이라고 예상하였기 때문이다. 반면 폐재를 재활용하는 파티클보드와 목재칩을 원료로 이용하는 펄프의 경우 전체적인 공급은 늘어날 것으로 전망된다.

• 한국물환경학회지
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• 제34권1호
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• pp.67-76
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• 2018

There are 34 mega-cities with a population of more than 10 million in the world. One of the highly populated cities in the world is Seoul in South Korea. Seoul receives $1,140million\;m^3/year$ for domestic water, $2million\;m^3/year$ for agricultural water and $6million\;m^3/year$ for industrial water from multi-purpose dams. The maintenance water used for water conservation, ecosystem protection and landscape preservation is $158million\;m^3/year$, which is supplied from natural precipitation. Recently, the use of the other water for preservation of water quality and ecosystem protection in urban areas is increasing. The objectives of this study is to develop the seasonal forecast method of environmental water in urban areas (Seoul, Daejeon, Gwangju, Busan) and to evaluate its predictability. In order to estimate the seasonal outlook information of environmental water from Land Surface Model (LSM), we used the observation weather data of Automated Synoptic Observing System (ASOS) sites, forecast and hind cast data of GloSea5. In the past 30 years (1985 ~ 2014), precipitation, natural runoff and Urban Environmental Water Index (UEI) were analyzed in the 4 urban areas. We calculated the seasonal outlook values of the UEI based on GloSea5 for 2015 year and compared it to UEI based on observed data. The seasonal outlook of UEI in urban areas presented high predictability in the spring, autumn and winter. Studies have depicted that the proposed UEI will be useful for evaluating urban environmental water and the predictability of UEI using GloSea5 forecast data is likely to be high in the order of autumn, winter, spring and summer.

• 한국물환경학회지
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• 제27권3호
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• pp.264-272
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• 2011

The objective of this study was to develop a model for predicting long-term runoff in a basin using the ensemble streamflow prediction (ESP) technique and review its reliability. To achieve the objective, this study improved not only the ESP technique based on the ensemble scenario analysis of historical rainfall data but also conventional ESP techniques used in conjunction with qualitative climate forecasting information, and analyzed and assessed their improvement effects. The model was applied to the Geum River basin. To undertake runoff forecasting, this study tried three cases (case 1: Climate Outlook + ESP, case 2: ESP probability through monthly measured discharge, case 3: Season ESP probability of case 2) according to techniques used to calculate ESP probabilities. As a result, the mean absolute error of runoff forecasts for case 1 proposed by this study was calculated as 295.8 MCM. This suggests that case 1 showed higher reliability in runoff forecasting than case 2 (324 MCM) and case 3 (473.1 MCM). In a discrepancy-ratio accuracy analysis, the Climate Outlook + ESP technique displayed 50.0%. This suggests that runoff forecasting using the Climate Outlook +ESP technique with the lowest absolute error was more reliable than other two cases.

• Ocean and Polar Research
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• 제34권2호
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• pp.185-195
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• 2012

This paper focused on forecasting a short-term production of oysters, which have been farmed in Korea, with distinct periodicity of production by year, and different production level by month. To forecast a short-term oyster production, this paper uses monthly data (260 observations) from January 1990 to August 2011, and also adopts several econometrics methods, such as Multiple Regression Analysis Model (MRAM), Seasonal Autoregressive Integrated Moving Average (SARIMA) Model, and Vector Error Correction Model (VECM). As a result, first, the amount of short-term oyster production forecasted by the multiple regression analysis model was 1,337 ton with prediction error of 246 ton. Secondly, the amount of oyster production of the SARIMA I and II models was forecasted as 12,423 ton and 12,442 ton with prediction error of 11,404 ton and 11,423 ton, respectively. Thirdly, the amount of oyster production based on the VECM was estimated as 10,425 ton with prediction errors of 9,406 ton. In conclusion, based on Theil inequality coefficient criterion, short-term prediction of oyster by the VECM exhibited a better fit than ones by the SARIMA I and II models and Multiple Regression Analysis Model.

• 대기
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• 제25권2호
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• pp.271-281
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• 2015

The objectives of this study are to develop a hydrological drought outlook system using GloSea5 (Global Seasonal forecasting system 5) which has recently been used by KMA (Korea Meteorological Association) and to evaluate the forecasting capability. For drought analysis, the bilinear interpolation method was applied to spatially downscale the low-resolution outputs of GloSea5 and PR (Predicted Runoff) was produced for different lead times (i.e., 1-, 2-, 3-month) running LSM (Land Surface Model). The behavior of PR anomaly was similar to that of HR (Historical Runoff) and the estimated values were negative up to lead times of 1- and 2-month. For the evaluation of drought outlook, SRI (Standardized Runoff Index) was selected and PR_SRI estimated using PR. ROC score was 0.83, 0.71, 0.60 for 1-, 2- and 3-month lead times, respectively. It also showed the hit rate is high and false alarm rate is low as shorter lead time. The temporal Correlation Coefficient (CC) was 0.82, 0.60, 0.31 and Root Mean Square Error (RMSE) was 0.52, 0.86, 1.20 for 1-, 2-, 3-month lead time, respectively. The accuracy of PR_SRI was high up to 1- and 2-month lead time on local regions except the Gyeonggi and Gangwon province. It can be concluded that GloSea5 has high applicability for hydrological drought outlook.

• 한국환경과학회지
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• 제27권3호
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• pp.147-154
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• 2018

The purpose of this article is analyzing the impacts of seawater surface temperature rise on sea mustard yields of Goheung and Wando coast in Korea, with employing a panel data regression model. Our results show that there has been a negative impacts on sea mustard yields as seawater surface temperature continuously has been rising. Especially if the upward trend in seawater surface temperature since 2005 will be maintained in future, sea mustard yield is expected to decrease by 2.6% per year.

• 응용통계연구
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• 제33권6호
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• pp.763-776
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• 2020

양파는 기상여건에 따른 작황의 변동성이 커 생산량 및 가격 변화가 크다. 정부는 양파를 수급 민감 품목으로 지정하여 다양한 수급 안정대책을 마련하고 시행하는데 이를 위해서는 선제적이고 신뢰도 높은 양파 생산량 예측 정보가 필수적이다. 본 연구에서는 양파의 5월 초 지상부 생육정보와 5월 초부터 수확기까지의 기상정보를 이용하여 최종 생구 무게에 미치는 영향을 추정함으로써 생산량 예측의 정확도 개선에 기여하고자 한다. 위계적 특성을 갖고 있는 자료를 통해 개체별 생육요인인 1-수준 자료와 필지별 기상요인인 2-수준 자료, 그리고 두 수준 간 상호작용을 고려한 다층모형을 도입하여 분석하였다. 분석 결과, 5월 초에 엽수, 엽초경, 초장의 생육이 좋을수록 최종 생구 무게는 증가하는 것으로 추정되었다. 5월 초부터 수확기까지의 기상요인에서는 강수량, 고온일수, 탄소동화저해일수가 생구 무게에 음의 효과가 나타났으며, 일교차와 수확전강수량은 양의 효과로 통계적으로 유의하였다. 또한 1-수준과 2-수준의 교호작용항을 고려하여 모형의 적합도와 설명력을 향상시켰다.

• 한국수자원학회논문집
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• 제48권7호
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• pp.581-593
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• 2015

본 연구에서는 ESP (Ensemble Streamflow Prediction)기법을 활용한 가뭄전망 체계를 구축하고 가뭄예보에 있어 활용성을 평가하였다. 과거 관측 수문기상 및 지형정보를 이용하여 우리나라 전역에 지면모델(Land Surface Model, LSM)을 구축하고 유출량(Historical Runoff, HR)을 생산하였다. 또한, 모의기간 동안 과거 30개 기상자료와 초기 토양수분량을 이용하여 선행시간별(1, 2, 3개월) 전망된 유출량(Predicted Runoff, PR)을 생산하였다. 평가결과 여름 및 가을철 보다 봄철 및 겨울철에 정확도가 높았으며, 1개월 전망 이후로는 정확도가 낮게 나타났다. 가뭄지수는 국내 가뭄해석에 있어 검증된 표준유출지수(Standardized Runoff Index, SRI)를 활용하였으며, PR_SRI을 산정 및 평가하였다. 1, 2개월 전망에서는 과거 HR이 고려되어 ESP HR에 비해 정확도가 크게 개선됨을 알 수 있었다. 선행시간별 상관계수는 평균 0.71, 0.48, 0.00, 평균제곱근오차는 0.46, 0.76, 1.01로 나타났으며, 건조기에 정확도가 높게 나타나 1, 2개월 전망까지는 ESP를 활용한 국내 가뭄예보의 활용성이 높다고 판단된다.

• 농업과학연구
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• 제48권1호
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• pp.83-93
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• 2021

The 52-hour workweek policy in Korea is a system that limits the maximum working hours per week to 52 hours including holiday work, which has been treated separately from overtime work during a week. Although this policy is designed to improve the quality of life and create jobs, it may also reduce the income of some workers. In general, it can be assumed that reduced working hours increase consumption at home. This study analyzed the effect of the 52-hour work policy on meat consumption patterns with the ordered logit model. Major factors considered in this study include working hours, income, and consumption frequency. It distinguished domestic and workplace consumption. The results show that the policy has had an impact on meat consumption patterns both at home and at work. If there is no change in income and only the working hours decrease, meat consumption in households increases. On the other hand, if both income and working hours decrease, household meat consumption decreases. Moreover, reduced working hours decrease the frequency of office happy hour and meat consumption in the workplace. However, the 52-hour workweek policy applies only to workers working more than 52 hours per week; thus, it is difficult to determine the overall effect of the policy on national meat consumption patterns.