• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.291-307
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• 2023

Medicinal crops are the most representative input among agricultural products for biomaterials. The actual situation of how medicinal crops are used as inputs in the downstream industry is analyzed, and the input demand function of medicinal crops is quantitatively estimated. The proportions of intermediate demand and final demand in the total production of medicinal crops were 52.1% and 47.9% in 1995, but changed to 74% and 26% in 2019, with the proportion of intermediate demand accounting for approximately increased by 3 times. Estimation results of the demand function for medicinal crops in the medicine industry show, a 1% increase in the production of medicine is found to increase the demand for medicinal crops by 0.3369%. If the production of health functional foods increase by 1%, the demand for medicinal crops is expected to increase by 0.6221%. It is also found that a 1% increase in the amount of cosmetic production would increase in the demand for medicinal crops by 0.3932%. This indicates that market expansion in downstream industries can have a significant impact on agricultural products for biomaterials.

• Environmental and Resource Economics Review
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• v.23 no.1
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• pp.43-65
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• 2014

In this paper, we test for allocative efficiency of productive inputs including electricity and measure the divergence between the actual and optimal level of electricity for the chemical products, which is a relatively highly electricity-intensive sector in Korean manufacturing industries, by estimating a shadow cost function. Supposing cost minimization subject to market prices was achieved, we derive the price elasticities of demand for each input and simulate the impact of a 10% increase in power rate on its demand and supply price by estimating jointly a cost function with an inverse supply relation. The null hypothesis of allocative efficiency of inputs is rejected over the period 1982-2006. On average, electricity is used more than optimal level by 98% per year. The demand for electricity decreases by 11.4%, and supply price, on average, falls by 0.08%, other things being equal.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.169-181
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• 2013

PURPOSES : This study is to suggest the Influence of road capital to industry and productivity growth in South Korea. METHODS : Based on the literature review, The relevant policy questions addressed in this report are : cost reduction and Scale elasticities of road, effect of road capital stock on demand for labor, capital and materials, marginal effect of road, industry TFP growth decomposition. RESULTS : The marginal benefits of the road capital at the industry level were calculated using the estimated cost elasticities. Demand for the road capital services varies across industries as do the marginal effects. The marginal benefits are positive for the principal industries. This suggests that for these industries the existing stock of road capital may be under supplied. The contribution of road capital to TFP growth is positive in principal industries. The main contribution of road capital is in the manufacturing industries ; the magnitudes of contribution varies among industries. These results indicate that growth in exogenous demand is most important contributor to TFP growth. CONCLUSIONS : The road capital have a significant effect on employment, private capital and demand for materials inputs in all industries. At a given level of output, an increase in road capital lead to variety to demand for all inputs in all industries.

• Journal of Agricultural Extension & Community Development
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• v.22 no.3
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• pp.285-292
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• 2015

Recently, the demand of rural tourism has been increased to promote farm household income and rural economy. Korean government has supported to promote rural tourism. One of the most difficult tasks in estimating the economic impact of the tourism industry is how the industry should be defined in terms of an economic sector, since tourism is not defined in national Input-Output (I-O) tables or in the Standard Industrial Classification code. Moreover, there is no specified Standard Industrial Classification for rural tourism. The purpose of the study aims to examine specified Standard Industrial Classification of rural tourism using the I-O model analysis to estimate the economic impacts of rural tourism. Results showed that there were two components considered as inputs. One is the inputs that final demand can move to input of rural tourism in I-O tables. The other is one that the final demand was provided by farm household as intermediate inputs.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.97.1-103
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• 2001

Railway passenger demand forecasts may be used directly, or as inputs to other optimization model which is use the demand forecasts to produce estimates of other activities. The optimization models require demand forecasts at the most detailed level. In this environment exponential smoothing forecasting methods such as Holt-Winters are appropriate because it is simple and inexpensive in terms of computation. There are several initialization methods for Holt-Winters Model. The purpose of this paper is to compare the initialization methods for Holt-Winters model.

• Management Science and Financial Engineering
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• v.6 no.2
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• pp.1-28
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• 2000

Supply chain management issues faced by a manufacturing company are considered in this paper. The supply chain consists of a manufacturing company and its suppliers. The manufacturer produces multiple products with inputs (e.g., raw materials) from the suppliers, but each product needs a different mix of these inputs. The market demand for the products is uncertain. We develop a mathematical model and algorithm, which can help the manufacturer to solve its procurement decision problem: how much of raw material to order from which supplier. The model incorporates such factors as market demand uncertainty, product's input requirement, supplier's as well as manufacturer's capacity, plus other costs comparable with those in a typical newsboy problem. Numerical examples are presented to see the interacting effects among critical parameters and variables.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.4
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• pp.135-149
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• 1994

Demand forecasting is to estimate the demand of customers for products and services. Since the future is uncertain in nature, it is too difficult for us to predict exactly what will happen. Therefore, when the forecasting is performed upon the uncertain future, it is realistic to estimate the value of demand as an interval or a fuzzy number instead of a crisp number. In this paper, we propose a demand forecasting method using the standard back-propagation algorithm and then we extend the method to the case of interval inputs. Next, we demonstrate that the proposed method using the interval neural networks can represent the fuzziness of forecasting values as intervals. Last, we propose a demand forecasting method using the transformed input variables that can be obtained by taking account of the degree of influence between an input and an output.

• Steel and Composite Structures
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• v.37 no.2
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• pp.151-173
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• 2020

This paper aims to probabilistically evaluate performance of two types of I beam to box column (IBBC) connection. With the objective of considering the variability of seismic loading demand, statistical features of the inter-story drift ratio corresponding to the second, fifth and eleventh story of a 12-story steel special moment resisting frames are extracted through incremental dynamic analysis at global collapse state. Variability of geometrical variables and material strength are also taken into account. All of these random variables are exported as inputs to a probabilistic finite element model which simulates the connection. At the end, cumulative distribution functions of local seismic demand for each component of each connection are provided using histogram sampling. Through a parametric study on probabilistic local seismic demand, the influence of some geometrical random variables on the performance of IBBC connections is demonstrated. Furthermore, the probabilistic study revealed that IBBC connection with widened flange has a better performance than the un-widened flange. Also, a design procedure is proposed for WF connections to achieve a same connection performance in different stories.

• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.9-13
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• 2004

Railway passenger demand forecasts may be used directly, or as inputs to other optimization models use them to produce estimates of other activities. The optimization models require demand forecasts at the most detailed level. In this environment exponential smoothing forecasting methods such as Holt-Winters are appropriate because it is simple and inexpensive in terms of computation. There are several initialization methods for Holt-Winters Model. The purpose of this paper is to compare the initialization methods for Holt-Winters model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1477-1485
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• 2018

There are two major issues for activated sludge process in sewage treatment plant. One is how to make sewage be more clean and the other is the energy saving in sewage treatment process. The major monitoring sewage qualities are chemical oxygen demand, phosphorus, nitrogen, suspended solid in effluent. These are transmitted to the national TMS(Telemetry Monitoring System) at every hour. If these exceed the environmental standard, the environmental charges imposed. So, these water qualities are to be controlled below the environmental standard in operation of sewage treatment plant. And recently, the energy saving is also important in process operation. Over 50% energy is consumed in blowers and motors for injection oxygen into aeration tank. So, with the water qualities to be controlled below the environmental standard, the energy saving also is to be accomplished for efficient plant management. Almost researches are aimed to control water quality without considering energy saving. AI techniques have been used for control water quality. AI modeling simulator provided the optimal control inputs(blower speed, waste sludge, return sludge) for control water quality. Blower speed is the main control input for activated sludge process. To make sewage be more clean, the excessive blower speed is supplied, but water quality is not better than the previous. In results, non necessary energy is consumed. In this paper we propose a new method that the energy saving also is to be accomplished with the water qualities to be controlled below the environmental standard for efficient plant management. Water qualities in only aeration tank are used the inputs of fuzzy models. Outputs of these models are chemical oxygen demand, phosphorus, nitrogen, suspended solid in effluent and have the environmental standards. In test, we found this method could save 10% energy than the previous methods.