• Economic and Environmental Geology
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• v.54 no.6
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• pp.733-741
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• 2021

Globally, in accordance with the goals set forth in the 2015 Paris Climate Agreement, each country has established and declared a reduction target for carbon neutrality by 2050. The roadmaps for establishing long-term greenhouse gas emissions development strategies and setting reduction targets have been announced. As the international community accelerates the transition to the net-zero society, 128 countries have declared net-zero by the end of 2020, and the net-zero declaration continues to expand around G20 member states. In December 2020, Korea announced the "2050 Net-zero Strategy" to establish a foundation for simultaneously achieving carbon reduction, economic growth, and improved quality of life for the people through active response to the net-zero, and pursuing policy tasks in stages to do this. Comprehensive carbon management is insufficient due to the lack of comprehensive carbon management due to the departure from the areas of mandatory reduction, such as the GHG energy target management system and the GHG emissions trading offset system implemented to reduce greenhouse gases in Korea. Currently, there is no cases for estimation or calculation of carbon dioxide emissions for the Mine Reclamation projects. It is reviewed the standard methods proposed by domestic and foreign carbon emission calculation methods and proposed appropriate carbon emission estimation methods for the Mine Reclamation projects in this study.

• Journal of Korean Association for Spatial Structures
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• v.7 no.3 s.25
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• pp.133-140
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• 2007

Spatial structures is a appropriate shape that resists external force with only inplane force by reducing the influence of bending moment, and it maximizes the effect of structure system. An economic analysis is one of the most important factors to determine the project feasibility. Large spatial structures project is more need to comprehensive technology than a general construction project. In order to result in success of these project, it is desired that analyze an essential elements(for example, large budget, professional engineer, construction method, etc.) in the whole life cycle of buildings by schematic preparation from the early feasible study steps. We collect the data and analyze construction cost through this study which examines general remarks of existing spatial structures and researches its examples. This study is aimed to apply basic data to establish database the spatial structures.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.57-71
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• 2009

Crop-livestock mixed farming systems depend on the efficiency with which nutrients are conserved and recycled. Home-grown forage is used as animal feed and animal excretions are applied to cultivated crop lands as manure. The objective of this study was to develop a mixed farming system model for dairy cattle in Japan. The model consisted of four sub-models: the nutrient requirement model, based on the Japanese Feeding Standards to determine requirements for energy, crude protein, dry matter intake, calcium, phosphorus and vitamin A; the optimum diet formulation model for determining the optimum diets that satisfy nutrient requirements at lowest cost, using linear programming; the herd dynamic model to calculate the numbers of cows in each reproductive cycle; and the whole farm optimization model to evaluate whole farm management from economic and environmental viewpoints and to optimize strategies for the target farm or system. To examine the model' validity, its predictions were compared against best practices for dairy farm management. Sensitivity analyses indicated that higher yielding cows lead to better economic results but higher emvironmental load in dairy cattle systems integrated with forage crop production.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.343-351
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• 2018

Renewable energy sources has drawn considerable attention as clean energy sources because of changing public attitudes regarding greenhouse gas and fine dust. Recently, in this respect, the government provides the drivers of electric vehicles with various benefits such as tax reduction, financial incentives and free parking from the public to the private sector. Plug-in electric vehicles are the most common in the private sector. Otherwise, different types of battery-based buses in the public sector are being developed, and there are three main types of charging: plug-in, battery swapping and wireless. Therefore, economic assessment of charging types in each bus route is required in order to facilitate the use of battery-based buses instead of the existing CNG buses. In this paper, net present value(NPV) and B/C ratio of charging types are evaluated in consideration of the bus schedule, the cost of charging station, and the life cycle of battery, etc. per each bus route. In case study, main bus routes in Daegu City are simulated with the proposed evaluation method to validate the eco-bus project.

• KIEAE Journal
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• v.15 no.1
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• pp.69-75
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• 2015

Building has required the repair money to improve or maintain the decent living condition continuously after construction. It needs to grasp the building deterioration to decide the scope and contents before it is repaired. Under various conditions such as physical, social and financial constraints, the repair plan would be prepared. Among constraints, the cost is indispensible to specify the repair time, repair scope and target. The required cost would be planned to preparation over the years. In this paper, it aimed at providing the repair strategy of the public rental housing in repair time, using the cumulative cost model which is $3^{rd}$ function. In the $3^{rd}$ function, the inflection point should exist in the line. And there are two types in the cumulative model, First, if the maximum cost be shown, the repair time would be provided. Second, if the maximum cost not be shown, the cumulative function should be proportionally increased and the repair strategy is properly provided with a short cycle. In results of this study, 11 items would provide the repair time. These cumulative function would be repaired about 4 years after constructed, and after about 4 years, the cumulative function would be continuously increased.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.93-102
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• 2010

Greening sometimes fails because its method is not suitable for various site conditions, therefore the trend of selecting a revegetation method in Korea today is through test construction. However, due to enlargement, complication and diversification of domestic construction businesses, the importance of VE is gradually increasing as effective efforts over a whole life-cycle to obtain goals such as quality improvement and cost reduction, and not only quality and economic efficiency but also substantiality need to be considered in comparing revegetation methods. For this study, Sungnam~Janghowon (area1), where comparatively various slope revegetation methods are used, was selected the investigation site. The site was divided into three areas:blasting rock, ripping rock and earth sand. The revegetation methods used were six in the blasting rock area, five in the ripping rock area, and two in the earth sand region. 2007 monitoring data was analyzed, and Value (V) was calculated with LCC related ratio, and compared and contrasted with the evaluation of prior revegetation methods. Therefore it is believed that this analysis enables selection of the most appropriate method, unbiased towards one particular characteristic such as quality, vegetation growth and economy. When aiming for a durable effect, it shall be more efficient to select the most appropriate method focusing on LCC analysis, which deals with the economic aspect, as well as the design function aspect.

• Journal of Labour Economics
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• v.36 no.3
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• pp.65-96
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• 2013

Analysis based on the Korea Labor and Income Panel Survey data reveals that earnings have become less volatile since the exchange rate crisis, while they have become more unequal. The reduction in measured earnings volatility is not explained by changes in the composition of various economic/demographic groups but accounted for by within-group reduction in the measured earnings volatility, which in turn is attributed to the reduced earnings mobility during the sample period. It is also found that measured earnings volatility is countercyclical and earnings changes are symmetric even during recessions.

• Journal of Distribution Science
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• v.16 no.6
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• pp.5-13
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• 2018

Purpose - The purpose of this paper is to look into some alternative for Korean shipping to overcome difficult situations in shipping, since then it is economic crisis at the end of 2000s. Research design, data, and methodology - The research method to be adopted is first to review theoretical overview about shipping cycle, and then examine difficult shipping situations and studies management aspect, which is to related to establishment of Korea Shipping Council. Results - The boom and bust situations in shipping market have been identified as result of economic crisis at the end of 2000s. Trade volumes have fallen and shipping tonnage has risen respectively. In practical terms, shipping industry has suffered from difficult situations, following to supply and demand of shipping market, and Korean shipping had to face hard time as well, according to lack of management ability of shipping company. Alternatively, it should be asked shipping forum like Korea Shipping Council. Conclusions - From situations of shipping markets since the end of 2000s, it is strongly asked that every parties got involved in shipping business should understand and share more expertise and knowledge of shipping market, which is finally related to decision- making process in shipping.

• KIEAE Journal
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• v.15 no.3
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• pp.57-63
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• 2015

Purpose: Ground source heat pump system has been attracted in the horticulture industry for the reduction of energy costs and the increasing of farm income. Even though it has higher initial costs, if it uses in combination with heat storage, it is able to reduce the initial costs and operate efficiently. In order to have significant effect of heat storage type ground source heat pump system, it is required to design the capacity considering various conditions such as energy load pattern and operating schedule. Method: In this study, we have designed heat storage type ground source heat pump system in 5 cases by the operating schedule, and examined the system to find the most economic and having superb performance regarding the system COP(Coefficient of Performance) and energy consumption, using dynamic energy simulation, TRNSYS 17. Result: Conventional ground source heat pump system has lower energy consumption than heat storage type, but following the result of LCC(Life Cycle Cost) analysis, the heat storage type was more economic due to the initial costs. In addition, it has the most efficient performance and energy costs in the case of the smallest heat storage time.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.218-223
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• 2009

Cost related to building equipment accounts for about 85% of the life cycle cost of buildings. Therefore proper selection of air-conditioning system is important for reducing the overall cost of buildings. In this study, large capacity ice thermal storage and absorption chiller-heater for air-conditioning a building with a floor area of $9,900\;m^2$ are compared economically. For easy input and analysis, an Ms Excel VBA program has been developed. To consider all the factors of initial and operation costs effectively, an annual equal payment method is proposed. Under the assumptions made in this study, overall cost of an absorption chiller-heater is less than that of an ice thermal storage, but this is not absolute and different outcome may result if different assumptions are made. This study is useful for those who are interested in choosing an economical air-conditioning system for large-size buildings with simple calculations.