• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.261-273
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• 2022

This study aims to predict the land use demand of Seongnam-city using system dynamics and to simulate the effect of changes in family structure and land use density adjustment policy on land use demand. This study attempted to construct causal loop diagrams and an analysis model. The changes in land use demand over time were predicted through simulation results. As a result of the analysis, as of 2035, an additional supply of 2.08 km² for residential land and 1.36 km² for commercial land is required. Additionally, the current supply area of industrial land can meet the demand. Three policy experiments were conducted by changing the variable values in the basic model. In the first policy experiment, it was found that when the number of household members decreased sharply compared to the basic model, up to 7.99 km² of additional residential land were required. In the second policy experiment, if the apartment floor area ratio was raised from 200% to 300%, it was possible to meet the demand for residential land with the current supply area of Seongnam-city. In the third policy experiment, it was found that even if the average number of floors in the commercial area was raised from four to five and the building-to-land ratio in the commercial area was raised from 80% to 85%, the demand for commercial land exceeded the supply area of the commercial area in Seongnam-city. This study is meaningful in that it proposes a new analytical model for land use demand prediction using system dynamics, and empirically analyzes the model by applying the actual urban planning status and statistics of Seongnam-city.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.373-377
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• 2006

By prosperous condition of construction economy in the early 90s in korea, we needed a lot of the qualified professional engineers(PE) to manage the construction site. In order to meet the high demand of P.E., government has established the admitted engineer system(AES) which is given to admitted engineer who do not take the written exam but have equivalent working experience in 1995. However, since 2000, while professional engineer's shortage has been resolved, the opposite situation has occurred that is serious over-supply of construction engineers. Thus, government announced that will abolish the admitted engineer systems as recognized existent admitted engineers. However, Professional Engineers institution is insisting that must not recognize existent admitted engineer. From this point of view, it is critical to make the supply-demand forecast systems as a derivative approach of system dynamics also, that is useful in comparing the argument between government and Professional Engineers institution. This paper describes about qualified engineer's supply change by admitted engineer system abrogation and suggests the idea to regulate the supply and demand with the improvement of the regal system.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.1-10
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• 2013

Major issues in water supply service have changed from expansion of service area to improvement of service quality, i.e., water quality and safety, and early response to emergency situation. This change in the service concept triggers the perceptions of limitation with the current centralized water supply system and of necessities of decentralized (distributed) water supply system (DWSS), which can make up the limitations. DWSS can reduce the possibility of water supply outage by establishing multiple barriers such as emergency water supply system, and secure better water quality by locating treatment facilities neighboring consumers. On the other hand, fluctuation of water demand will be increased due to the reduced supply area, which makes difficult to promptly respond the fluctuating demand. In order to supplement this, hybrid water supply system was proposed, which combined DWSS with conventional water supply system using distributing reservoir to secure the stability of water supply. The Optimal connection point of DWSS to existing water supply network in urban area was determined by simulating a supply network using EPANET. Optimal location of decentralized water treatment plant (or connection point) is a nodal point where changes in pressure at other nodal points can be minimized. At the same time, the optimal point should be selected to minimize hydraulic retention time in supply network (water age) to secure proper water quality. In order to locate the point where these two criteria are satisfied optimally, Distance measure method, one of multi-criteria decision making was employed to integrate the two results having different dimensions. This methodology can be used as an efficient decision-support criterion for the location of treatment plant in decentralized water supply system.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.147-154
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• 2024

The continuous increase in urban population due to migration of mases from rural areas to big cities has set urban water supply under serious stress. Urban water resources face scarcity of available water quantity, which ultimately effects the water supply. It is high time to address this challenging problem by taking appropriate measures for the improvement of water utility services linked with better understanding of demand side management (DSM), which leads to an effective state of water supply governance. We propose a dynamic framework for preventive DSM that results in optimization of water resource management. This paper uses Agent Based Modeling (ABM) with Digital Twin (DT) to model water consumption behavior of a population and consequently forecast water demand. DT creates a digital clone of the system using physical model, sensors, and data analytics to integrate multi-physical quantities. By doing so, the proposed model replicates the physical settings to perform the remote monitoring and controlling jobs on the digital format, whilst offering support in decision making to the relevant authorities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4B
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• pp.233-242
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• 2012

In the past, the domestic water supply benefit of dam has been estimated by replacement dam cost approach. But it is logically inappropriate that we use the second priority dam as a replaced facility. Therefore, this study aims to suggest the estimation method of the domestic water supply benefit by using demand function, which is deduced from Willingness-To-Pay (WTP) of consumers. For this purpose, a survey concerning the marginal WTP is carried out according to the change of water use amount used, targeted 1,000 households in metropolitan area. And by using the marginal WPT, we estimated the demand function of a family. Finally, the monthly benefit equation is derived. The approach is demonstrated and discussed for an example, the Song-Li-Won dam project which is now renamed Young-Ju dam. From the example study, the total benefit for the durable years (50 years), was about 90 billion won. The method proposed herein is expected to be practical and useful in the economic analysis of the domestic water supply project including dam construction, as well as in further studies.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.16-24
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• 1980

The purpose of this study is to analyse the demand-supply structure and its trend of the paper production in Korea. The ratio of paper was calculated to analyse the demand-supply structure. The cross-section and the time series analysis were adopted to analyse the demand-supply trend. The results obtained are summarized as follows: 1. In consumption ratio of paper the board paper was the highest, in export ratio the print paper was the highest. 2. In 1979, the consumption of paper was 45kg/capita, which were very high value comparing with the level of gross national products in Korea. 3. The elasticity of income and price in paper consumption per capita was 1.67 and -0.73, respectively. The more the GNP increases, the more the industrial paper demand rises rapidly.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.17-42
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• 2008

This study tried to build a structure model for the Korean flatfish aquaculture market by a system dynamics approach. A pool of several factors to influence the market structure was built. In addition, several reasonable factors related to the flatfish aquaculture market were selected to construct the causal loop diagram (CLD). Then the related stock/flow diagrams of the causal loop diagrams were constructed. This study had been forecasting a production price and supply, demand, and consumption volume for the flatfish market by a monthly basis, and then made some validation to the forecasting. Finally, four governmental policies such as import, storage, reduction of input, and demand control were tentatively evaluated by the created model. As a result, the facts that the demand control policy is most effective, and import and storage policies are moderately effective were found.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.758-762
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• 2007

Revenue management is a new approach method to solve the problem of supply and demand, and one of fields which is diffused quickly at the service enterprise to use perishable-asset like the transportation business. It is based on multiple fare policy that discount charge reservation should be received if the benefit value of current discount fare is more than expected profit of the normal fare reservation it will be able to occur in future when suitable goods is sold to the customers at discount fare, at the time they want, and at assigned seat by controlling supply and demand from market. In this research, I will review on initial operation case for special class goods that the seat which is limited is assigned at some of train and portion of KTX for demand dispersion and new demand creation at peak time, put a limit in purchase conditions, and provides discounted fare. I will also try to find implication for strategic operation.

• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.189-209
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• 2004

The collaboration between businesses in a demand chain has three layers: Integration, Exchange, and Synchronize. The latter the layer is, the stronger the collaboration gets. This paper investigated drivers influencing intelligent demand chain integration strategy (supply integration, demand integration, demand chain integration) in Korea manufacturing and services. The drivers are classified into two types: rational efficiency driven and bandwagon driven. We find tile differences in the characteristics of drivers affecting the strategies. Besides, this study suggests the better integration strategy for Korea firms. In conclusion it says that demand integration strategy is chosen to improve efficiency, whereas supply integration strategy is influenced by external pressure.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.343-348
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• 2002

We are concerned with a long-term replenishment contract for the ARIMA demand process in a supply chain. The chain is composed of one supplier, one buyer and consumers for a product. The replenishment contract is based upon the well-known (s, Q) policy but allows us to contract future replenishments at a time with a price discount. Due to the larger forecast error of future demand, the buyer should keep a higher level of safety stock to provide the same level of service as the usual (s, Q) policy. However, the buyer can reduce his purchase cost by ordering a larger quantity at a discounted price. Hence, there exists a trade-off between the price discount and the inventory holding cost. For the ARIMA demand process, we present a model for the contract and an algorithm to find the number of the future replenishments. Numerical experiments show that the proposed algorithm is efficient and accurate.