• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제10권6호
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• pp.773-783
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• 1998

The heating system for apartment complex may be classified as old systems including central system with steam boiler(S1), gas engine driven heat pump system(S2), system using waste heat(S3) and new systems including mechanical vapor re-compression system with flashing heat exchangers(S4), system using methanol(S5), system using metal hydride (S6). The purpose of the present study is to suggest optimal heating system by technically, economically and environmentally evaluating old and new heating systems of apartment complex from 500 to 3,000 households. Economic evaluation based on the technical evaluation results which estimated heat transfer area of heat exchangers and capacity of equipments was estimated initial investment cost, annual operating cost and relative payback period by considering annual increasing rates of energy cost and interest. Environmental evaluation provided annual generation rate of carbon dioxide. Initial investment cost was cheap in the order of S6, S5, S3, S2, S4, S1, annual operating cost was cheap in the order of S1, S2, S4, S5 and relative payback period was short in the order of S6, S5, S2, S3 and S4. Relative payback period was within 8 years for all scenarios of 3,000 households, and was increased as annual increasing rates of energy cost and interest were increased. As transportation pipe length was increased twice, payback period was increased by 1.4~2.6 time. The effect of temperatures of waste gas and waste water on the relative payback period was small within 0.8 years. The annual generation rate of carbon dioxide was big in the order of S4, S2 and S1. S4 was the most economic system among whole scenarios when S1 was replaced with other scenarios.

• Proceedings of the KIEE Conference
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.975-979
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• 1988

This paper summarizes economic considerations for building automation. While the market for energy management systems(EMS) has been exploding, there are many indications that the pendulum of hight expectations may have swung too far. This is a very important reason for energy management system in both existing and new buildings. Because facilities continue to expand in size and their operations grow more complex, the use of automated systems to control and monitor both programmable and nonprogrammed function becomes an economic necessity. The following is offered as engineerings of economic consideration for building automation systems. Not only get a complete return on investment but increase profits in a few years through savings incurred in labor, utilities fuel and extended equipment life.

• International Journal of Computer Science & Network Security
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• 제22권7호
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• pp.181-190
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• 2022

The article contains an overview of the results of recent research by think tanks in different countries, devoted to the analysis of economic resilience factors in the Covid-19 crisis and the development of recommendations for improving preparedness for the next crises. The authors consider and propose a theoretical framework for the concept of the resilience of economic systems. The impact of the COVID-19 crisis on national economies is analyzed. Factors explaining the different cability of economic systems to withstand shock in the short and long term are identified. The reactions of market participants and national governments to the crisis are assessed. It is shown how the COVID-19 crisis has affected the digital transformation of economic systems, and how digital transformation helps to increase the resilience of national economies so that the latter can emerge from the crisis even stronger.

• Journal of the Korean Operations Research and Management Science Society
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• 제28권1호
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• pp.115-129
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• 2003

This paper Is concerned with a new techno-economic model Ing of ATM based h19h-speed networks. Coupled with advances of technology, the rapid development of new telecommunication services significantly increases the magnitude of risk in making an Investment decision. Naturally, the success of techno-economic modeling depends on how effectively we manage underlying risk factors such as cost and technology To deal with risk factors, we need to rely on modern decision and risk analysis while Implementing mathematical optimization for solving a complex capacity expansion problem of telecommunication systems during the planning period. We provide a case study that will enhance our understanding of the techno-economic analysis for emerging telecommunication systems.

• Asian Journal of Innovation and Policy
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• 제11권1호
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• pp.110-147
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• 2022

Many megacities are exposed to natural hazards such as earthquakes, and when located in coastal regions, are also vulnerable to hurricanes and tsunamis. The physical infrastructures of transportation systems in megacities have become so complicated that very few organizations can understand their response to extreme events such as earthquakes and can effectively mitigate subsequent economic downfalls. The technological advances made in recent years to support these complex systems have not grown as fast as the rapid demand on these systems burdened by population shift toward megacities. The objective of this paper is to examine the risks imposed on and recoveries of transportation systems in megacities as the result of extreme events such as an earthquake. First, the physical damage to transportation infrastructure, loss of the transportation system performance, and the corresponding economic loss from disruptions to passenger and freight traffic is evaluated. Then, traffic flows are re-routed to reduce vehicles' delay due to earthquakes using a microscopic traffic flow simulator with an optimization model and macroscopic terminal simulator. Finally, the economic impact of the earthquake is estimated nationwide. Southern California is regarded as the region of study. The results demonstrate the effectiveness of the integrated model and provide what and how to prepare innovative resilience policies of urban infrastructure for a natural disaster occurrence.

• Health Policy and Management
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• 제26권4호
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• pp.246-255
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• 2016

The study of public health systems is an important, but very difficult task. The concept and functions of public health systems are influenced by the views, interests, and influence of the various stakeholders belonging to public health systems and broader social, economic, political, and environmental sectors. To define public health system with conceptual clarification, we must take into account the dynamic and complex aspect of the public health system. This paper reviews health systems and public health systems literature to suggest the concept, goals, and functions of public health systems. In addition, this paper recognizes some challenges, such as leadership and management, resource development, economic support, and service delivery to strengthen public health systems for improving health and well-being of population.

• Korean Journal of Organic Agriculture
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• 제13권2호
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• pp.129-143
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• 2005

Attempting to make an economic valuation of semi-liquid manure raises various complex questions. These are the valuation under different farming conditions, cost-benefit analysis in connection with the investment requirements of different semi-liquid manure systems, different storage capacities, transportation distances and treatment procedures. In the following, there questions will be discussed : 1. What value do the different types of semi-liquid manure have under different farming conditions? 2. Which storage capacities are economically justified? 3. Under which conditions is the transport of semi-liquid manure over long distances profitable?

• Korean System Dynamics Review
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• 제6권1호
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• pp.147-176
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• 2005

This paper attempts to analyse the financial validity of the Eco-therapy project which 'J' city in 'C' province has been eagerly trying to implement for its regional economic development and also to estimate the potential economic impact of the project on its regional economy. In doing so, it employs system dynamics which is a methodology for studying and managing complex systems, such as one finds in business and other social systems. Analytic framework for this study is constructed, based on the existing theoretical studies. This study concludes that the Eco-therapy Project concerned is economically and financially valid and it is also expected that the regional economic impacts arising from the construction and operation of the facilities concerned are greater than any other project which 'J' city has been pursuing.

• Journal of Korean Society of Rural Planning
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• 제18권2호
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• pp.13-26
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• 2012

This study aims to present the policy issues and direction of sub-urban residential complex by analyzing the settlement environment and life satisfaction. For the purpose, 10 sub-urban residential complexes in Chungnam Province were surveyed for general situation, physical environment, social environment, economic environment. The results are as follows; 1) The satisfaction in the physical environment is more higher in case of the complex created by the public organization. 2) The physical environment is an important factor in the determinant of the settlement, while the economic environment have a relatively lower impact. 3) The residents community is the more active, the satisfaction in the social environment is the more improved. 4) The source of income or the activity of consumption doesn't have an effect on the satisfaction in the economic environment. On the basis of this study, three programs for improvement of sub-urban residential complex policy were suggested. First, the various information and counseling service should be provided to attract city dwellers. Second, the policy on the development of sub-urban residential complex has to consider residential preference factors and improve the quality of life. Third, to increase the life satisfaction, the residents community should be activated and especially the activation of community with residents in other village is very important.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.582-588
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• 1993

A scheme of dynamic optimization for batch reactor his been developed and applied to a semi-batch esterification reactor. To obtain optimal operating conditions for the given semi-batch reactor system with complex reaction kinetic and process constraints, a general nonlinear programming solver and finite element techniques have been introduced. The optimization results for the complex reactor system have been compared with those of Kumar et al. [1984] to show better optimization performance. The proposed optimizing scheme has been applied to the free end time problem to obtain the realistic operating condition. The results can supply valuable information for economic operation of the given batch esterification reactor.