• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.154-155
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• 2016

Although there is an increase in demand for free-form buildings, there are several problems such as increased cost and duration and decreased constructability arising from difficult member production and installation. To solve these problems, a technology to produce free-form panels using CNC machine was developed. According to the technology, the information on free-form buildings designed is delivered to the CNC machine, a form is shaped using the delivered information and free-form concrete panels are produced using the form. The limited construction site, duration and project cost as well as interferences with other work types should be considered upon in-situ production of free-form concrete panels. Thus, the purpose of this study is to conduct a base study on in-situ production layout of free-form concrete panels by system dynamics. With this study, we will discover the causal relationship of influence factors on in-situ production of free-form concrete panels, and improved productivity is expected through the production layout.

• Journal of Korean Academy of Nursing
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• v.48 no.5
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• pp.554-564
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• 2018

Purpose: This study aimed to construct a management model for patient transfer in a multilevel healthcare system and to predict the effect of counseling with nurses on the patient transfer process. Methods: Data were collected from the electronic medical records of 20,400 patients using the referral system in a tertiary hospital in Seoul from May 2015 to April 2017. The data were analyzed using system dynamics methodology. Results: The rates of patients who were referred to a tertiary hospital, continued treatment, and were terminated treatment at a tertiary hospital were affected by the management fee and nursing staffing in a referral center that provided patient transfer counseling. Nursing staffing in a referral center had direct influence on the range of increase or decrease in the rates, whereas the management fee had direct influence on time. They were nonlinear relations that converged the value within a certain period. Conclusion: The management fee and nursing staffing in a referral center affect patient transfer counseling, and can improve the patient transfer process. Our findings suggest that nurses play an important role in ensuring smooth transitions between clinics and hospitals.

• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.29-38
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• 2007

Recently, the deepening of the environment and accompanying concerns produce various environmental regulations. For example, EPR(Extended Producer Responsibility) is emphasized in many countries such as USA and Europe. According to this, the construction of a reverse supply chain is under compulsion. A diversity of parts can be controlled by a government or enterprises in the construction and management of a reverse supply chain and the effect to the environment is changed according to the policy. Therefore, it is essential to understand the effects of regulations or policies of a government and enterprises on a supply chain. The object of this research is to develop a means to assess the management efficiency and the environmental effect over a whole supply chain and show the effects of various reverse supply chain construction policies on a supply chain. This model can be utilized to establish appropriate policies by understanding the change in the management efficiency and the environmental effect according to the reverse supply chain construction and management method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.502-512
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• 2019

To examine the problem structure of balanced regional development policy and identify the causes of the gap between the capital and non-capital areas, this study examined the causal structure in terms of the concentration and distribution of functions in the metropolitan area and non-capital area and explored the policy leverage. As a research method, the causal map was drawn using System Dynamics techniques and policy leverage was derived through an exploration of the feedback structure. In particular, the causes of the problems in balanced regional development policies were approached by system accidents rather than by single-circuit accidents, and causality analysis was performed among the variables constituting balanced regional development policies based on system accidents. In particular, it singled out 31 variables, developed 13 feedback loops, and confirmed four major policy leverages, including relocation of the capital function, local decentralization policies, consistent development, and investment practices centered on the Non­Capital Area. Subsequently, a follow-up study by computer simulation is needed by modeling the structure of the system to identify the ripple effect of the policies of the Capital Area on the Non­Capital Area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.239-245
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• 2012

The necessity of professional construction management has been increased as a construction project is getting larger, more complex and specialized. Thus, the CM market has steadily expanded since 1996 in Korea. Despite the external expanding of the CM market, experts claim that domestic CM regulations and infrastructures should be revised. Therefore, this paper developed a causal map which consists of elements vitalizing CM market. Then, the simulation model using NUMBER (Normalized Unit Modeling by Elementary Relationships) to predict the size of the CM market is established. As a result, in the case of more regulation related CM, the quantity of CM projects could not reach of construction supervision until 2020. This paper can be used as a baseline providing a prospection of the change of CM market according to causal relation between the improvement as well as the base of revitalization research of CM market based on non-institutional factors change.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.115-127
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• 2006

Although the Korean government have made a plan of housing market with supply and concentrated on the welfare of the people, there are still a lot of problem in housing market for lack of a long-term vision and consistent policy of the government. The plan of 115% of housing diffusion in 2012 is in progress after its acquisition of 100% in 2002, but there are no changes in the rental housing rate of 43% in 2003. In addition, there are getting worse circumstances in the instability of housing market and the low-income bracket, because of the Korean construction firms' bankruptcy with an increase of unsold hosing and a rapid increase of housing prices. The government have made the strategy of revitalizing the economy and regional development by means of a million public rental housing plan for the low-income bracket and welfare. This paper introduces the basic information of the subjective strategy establishment with the analysis of the reciprocal action of influence factors for public rental housing by system dynamics theory and the effect of public rental housing in housing supply market which has a long-term dynamic form.

• Korean Journal of Construction Engineering and Management
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• v.7 no.6
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• pp.141-150
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• 2006

As the law on the private sector investment in social infrastructure was amended in January of 2005, the government is aggressively promoting BTL projects but many trials and errors and problems are occurring. Especially, the Value-For-Money evaluation conducted by the responsible agencies to judge the appropriateness of the project found there was a conspicuous difference between the computed cost and the final contract sum. Accordingly, this study is aimed to grasp the problems in the current Value-For-Money evaluation and to improve it in order to proceed with BTL projects efficiently. To achieve this, through a relative comparison to the final contract sum, a clear standard for the items of Value-For-Money evaluation was presented and thus, a model that can ensure accuracy in computing the Value-For-Money was established so that a delay in negotiations can be avoided. If the Value-For-Money evaluation established in this study is used in assessing the appropriateness of unit prices for BTL projects for education facilities, a reasonable result can be expected to be drawn in selection and negotiations with contractors, and maintenance and Post-Operation-Evaluation(POE) of education facilities as well.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.87-91
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• 2006

After reformation of 'the law of private investment on social infrastructure' on January 2005, BTL of educational facilities can improve the education circumstance at early stage, however there are trial and error, problems of execution as well. The key of this problem is not only related to whether BTL project is more reasonable, but it also leads to the proper performance of eligibility analysis on BTL. Therefore, it lead to the proper carryout of eligibility analysis on BTL. In order to promote effective BTL project of educational facilities, this study analyzes problems of existing model and creates the evaluation model for solving this problem. In this study, the evaluation model of investment on BTL has more quick ,accuracy and useful effect than previous one, if it is applied on eligibility stage. Moreover, this method could be applied to public building, SOC facilities effectively based on being modified as each characteristics of structure suitably.

• Korea Trade Review
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• v.48 no.3
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• pp.217-242
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• 2023

This study aims to analyze the factors influencing the logistics demand of inland ports along the Yangtze River and predict future port logistics demand based on these factors. The logistics demand prediction using system dynamics techniques was conducted for a total of six ports, including Chongqing and Yibin ports in the upper reaches, Jingzhou and Wuhan ports in the middle reaches, and Nanjing and Suzhou ports in the lower reaches of the Yangtze River. The logistics demand for all ports showed an increasing trend in the mid-term prediction until 2026. The logistics demand of Chongqing port was mainly influenced by the scale of the hinterland economy, while Yibin port appeared to heavily rely on the level of port automation. In the case of the upper and middle reach ports, logistics demand increased as the energy consumption of the hinterland increased and the air pollution situation worsened. The logistics demand of the middle reach ports was greatly influenced by the hinterland infrastructure, while the lower reach ports were sensitive to changes in the urban construction area. According to the sensitivity analysis, the logistics demand of ports relying on large cities was relatively stable against the increase and decrease of influential factors, while ports with smaller hinterland city scales reacted sensitively to changes in influential factors. Therefore, a strategy should be established to strengthen policy support for Chongqing port as the core port of the upper Yangtze River and have surrounding ports play a supporting role for Chongqing port. The upper reach ports need to play a supporting role for Chongqing port and consider measures to enhance connections with middle and lower reach ports and promote the port industry. The development strategy for inland ports along the Yangtze River suggests the establishment of direct routes and expansion of the transportation network for South Korean ports and stakeholders. It can suggest expanding the hinterland network and building an efficient transportation system linked with the logistics hub. Through cooperation, logistics efficiency can be enhanced in both regions, which will contribute to strengthening the international position and competitiveness of each port.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.2
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• pp.92-104
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• 2015

In order to analyze the impacts of climate change, a time and space integrated model was developed in this study using system dynamics and GIS. The model built was used to carry out a simulation on the inundation impact on A-gu of Busan Metropolitan city resulting from the sea level rise scenario of IPCC and storm surge, which is the worst case. Through this, the flooded area and population until 2100 were predicted. Also, the result and significance of each alternative was reviewed improving the model by establishing alternative scenarios of protection, accommodation and retreat as plans of reaction to sea level rise. The combination of system dynamics and GIS has advantages of how the diverse variables change until the target year can be traced and, accordingly, not only the results but also the processes of spatial change can be examined by calculating the value of change process at each time step. The synergy of this model presumed to be a foothold for solving problems which are becoming difficult to predict due to increase in uncertainty and complexity such as the support for decision making for urban resilience to natural disasters.