• Journal of Climate Change Research
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• v.8 no.1
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• pp.21-30
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• 2017

Recently, There has been much discussed about unused space. This space can be used in a variety of ways. Utilizing it as a facility, craft shop, and utilizing renewable energy generation facilities. Especially, in terms of climate change should be supplied renewable energy. Renewable energy needs to be developed in terms of responding to climate change, and the recent Paris agreement is also emphasizing the importance of renewable energy. In particular, renewable energy needs to be widely disseminated. And renewable energy is limited space. In this regard, idle land can provide opportunities for securing new renewable energy generation facilities. The introduction of new and renewable energy facilities in idle space can enhance the self-sufficiency rate of the local community, which is significant in terms of responding to climate. In this study, to investigate the possibility of utilizing a unused space for a photovoltaic power generation facility, we investigated the amount of electricity which could be generated through photovoltaic power generation, and the economic effects, using a RETScreen model. The results showed that 9,738 MWh of power can be generated and that $4,540tCO_2eqcan$ be saved. Regarding the economic effect, the net present value of the facility was shown to be 2,247,389,020 KRW. As the net present value was shown to be positive, we believe that the installation of a photovoltaic power generation facility in an unused space would have a positive economic effect. We found the net present value following the fluctuation of the SMP price to be positive, though there was some variation. However, as the economic efficiency was shown to be low because the net present value in relation to the maintenance costs was negative, we believe that maintenance costs must be taken fully into account when evaluating economic efficiency. In particular, as subsidies can be used to cover maintenance costs which must be factored into photovoltaic power generation, we believe that photovoltaic power generation can have an economic effect. Because spaces not currently in use can have a positive economic effect as renewable energy power generation facilities, and can also contribute to the reduction of greenhouse gas emissions, unused spaces are thought to greatly help local governments to cope with climate change as well as reinforcing their related capabilities. We believe our study will help local governments with decisions relating to unused real estate utilization in the future.

• Korean Journal of Construction Engineering and Management
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• v.24 no.6
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• pp.45-52
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• 2023

Recently, as climate change caused by greenhouse gases is intensifying, the international community has committed to reduce greenhouse gas emissions. The purpose of this study is to present the methodology and major considerations for investment judgment. Two actual cases of overseas projects were selected as study subjects. As an analysis method, the major risk factors were defined as a probability distribution, and the NPV was stochastically estimated using the Monte Carlo simulation method. In addition, assuming a policy change, the range of NPV change was analyzed. As a result, the average NPV of project A was lowered by 19%, and the probability of showing a negative NPV was 12.2%. The average value of project B was lowered by 12.5%. Considering the policy change, project A can obtain economic benefits only when it obtains 72.9% or more of the total amount of carbon credits generated, and project B is economically feasible when it acquires 49.5% or more. As a result, the average value of project A is lower than the net present value under basic assumptions, so caution is needed in investment decisions depending on changes in major risk factors. Additionally, considering policy changes, the carbon credit distribution ratio should be differentially applied depending on the project size, and this was presented as a specific figure.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.417-424
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• 2000

We applied SP monitoring and resistivity surveys using the pole-pole electrode array to seawater leakage problems in the Youngsan estuary dam and the Eoeun embankment to estimate and detect the zone of seawater leakage. The embankment is generally affected by tidal variation and has low resistivity characteristics due to the high saturation of seawater. For this reason, SP monitoring and the pole-pole array resistivity surveys, which are relatively more effective to the conductive media, were carried out to delineate the leakage zones of sea water through the embankment. We checked out electrical conductivity (EC) and temperature variations along the inner part of Youngsan estuary dam to detect the zone of seawater leakage and found that the measured EC value agreed to that of seawater in the leakage zone and the temperature was lower than that of the vicinity of leakage zone. SP monitoring results were coincided with tidal variations at each embankment. At the leakage zones in the Youngsan estuary dam and the Eoeun embankment, SP anomalies are in the range of -60~-85 mV and -20~-50 mV, respectively, and true resistivity values obtained by 2-D inversion are 3~15 ohm-m and below 0.3 ohm-m, respectively. Both SP monitoring and the pole-pole array resistivity method are found to be quite effective for investigation of seawater leakage zones in the embankment.

• Economic and Environmental Geology
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• v.13 no.3
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• pp.159-166
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• 1980

A model study was conducted for the investigation of apparent resistivity variation along with electric resistivity variation of host rock and dip variation of bed. Experiments were carried out for the cases of horizontal and dipping beds in a water tank by using Wenner and Schlumberger arrays and by changing salinity of water. The ratios of resistivity values of the bed to that of brine were 1 : 10, 1 : 50, 1 : 100 and 1 : 500. Natural coally-shale of $55cm{\times}35cm{\times}3.5cm$ was used as a bed for experimental model, and brine as a host rock. Equi-resistivity curves and characteristic curves were obtained for each case of the experiment. The equi-resistivity curve was drawn both on the cross section parallel to strike of bed and longitudinal section perpendicular to it. The characteristic curve was drawn on the cross section. In the case of dipping bed of different dips, the curves are parallel to the boundary of the bed in the upper part of the bed, and are inclined to the opposite direction with the same angle of the dip of bed in the lower part. We can deduce, from the equi-resistivity curves, the location, shape and dip of the bed. It is shown in the characteristic curves that when the ratio of resistivity value of bed to that of host rock increases, the slope of curves becomes steeper, location of low-resistivity zone lower, and the width of it narrower. The slope of curves also becomes steeper when dip of bed increases. We can deduce, from the characteristic curves, the ratio of resistivity values between adjacent beds. It was found out from the experiments that electric resistivity method could be applicable to prospecting for underground geology with an electric resistivity contrast of 1 : 10. This fact strongly suggests that distinction of coal from coally-shale could be possible in a certain field condition.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.37-45
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• 2016

Control chart is representative tools of statistical process control (SPC). It is a graph that plotting the characteristic values from the process. It has two steps (or Phase). First step is a procedure for finding a process parameters. It is called Phase I. This step is to find the process parameters by using data obtained from in-controlled process. It is a step that the standard value was not determined. Another step is monitoring process by already known process parameters from Phase I. It is called Phase II. These control chart is the process quality characteristic value for management, which is plotted dot whether the existence within the control limit or not. But, this is not given information about the economic loss that occurs when a product characteristic value does not match the target value. In order to meet the customer needs, company not only consider stability of the process variation but also produce the product that is meet the target value. Taguchi's quadratic loss function is include information about economic loss that occurred by the mismatch the target value. However, Taguchi's quadratic loss function is very simple quadratic curve. It is difficult to realistically reflect the increased amount of loss that due to a deviation from the target value. Also, it can be well explained by only on condition that the normal process. Spiring proposed an alternative loss function that called reflected normal loss function (RNLF). In this paper, we design a new control chart for overcome these disadvantage by using the Spiring's RNLF. And we demonstrate effectiveness of new control chart by comparing its average run length (ARL) with ${\bar{x}}-R$ control chart and expected loss control chart (ELCC).

• Asia pacific journal of information systems
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• v.20 no.3
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• pp.33-49
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• 2010

We empirically examine the impact of online auction knowledge and category-specific knowledge on the final price of online auctions. Specifically, we question how the relationship between buying and selling experiences affects the final prices of online auctions. Related to the trust between buyers and sellers, we examine the multiple interactions between a buyer-seller pairand aim to identify how these repeated transactions influence the final price. To contrast these effects with other product related factors, we focus on so called 'common value' auctions of vintage stamps on eBay, in which the ex-post value of the product is the same among participating agents’ perceived value. Online auction of stamps provides a representative setting to examine the relationship between market experience and the auction participation behavior in the common value auction, as it provides the book value of stamp as well as price variation across individual buyers with different expertise levels. Our analysis of over 3000 stamps auctions on eBay indicates a significantly high frequency of buyer-seller (pair) interactions, thus suggesting a 'relationship view' of auctions. The work validates five hypotheses derived from the existing theory in economics, marketing, and information systems. Through the common-value auction data, we find that seller's online auction experience and category-specific experience favor sellers by increasing the final price. However, buyer's online auction experience does not affect the final price, but buyer's category-specific experience favors buyers by decreasing the final price. We find that the trust between two trading parties increases the final price.

• Economic and Environmental Geology
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• v.32 no.3
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• pp.273-280
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• 1999

In order to protect inhabitans' health and to collect data for prediction of the effcts from accidental emission of rasioactive materials from nuclear power plant, exposed dose rate be monitored within the limit dose rate. This research was carried out to investigate the accumulation of environmental radioactivity around Younggwang Nuclear Power Plant, and to infer and in infer and assay the additional exposed dose rate of inhabitants in Younggwang site from the operation of nuclear plant operation. External radiation dose rate, radiation environmental samples, and exposed dose rate of inhabitants in Younggwang site were investigated for estimaing environment activity in the vicinity of the nuclear power plant area. For the external radiation dose rate, the result showed that range of normal variation was found and any artificial radioisotope was not deteted in the analysis of environmental samples. Exposed dose rate of inhabitants was lower than 0.4% of the limit value of ICRP and it may be concluded that there was no effect on inhabitants and environment from the operation of nuclear power plant.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.3
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• pp.359-365
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• 1998

An economic process monitoring procedure is presented when the major quality characteristic of the item is dichotomous. Every item is inspected and decided whether it is conforming or not. If an item is found to be nonconforming, the previous number of the successive conforming items is compared with a predetermined number r to check the process for existence of any assignable cause of variation. A cost model is constructed on the basis of costs of inspection, illegal signal, undetected out-of-control state and corrective action. By minimizing the expected total cost per unit time, the optimal value of r is obtained. The effects of cost coefficients are studied numerically.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.732-737
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• 2001

The mathematical method was developed and numerical analyses were carried out with various parameters to provide substantial data for optimal design and operation of urban utility systems. The composition of systems and their specifications, such as co-generation system, heat pump system, incineration system and other heating and cooling system could be obtained through these analyses for various resource and energy requirements in urban area. As results the system constituents and operating characteristics, and their economic performances such as the value of objective function, initial and an operating costs were discussed for various load patterns. The effective system design method and the excepted effects of the several unused energy recovery systems were also briefly discussed with the variation of the buildings and facilities species and their capacities.

• Economic and Environmental Geology
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• v.13 no.1
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• pp.21-27
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• 1980

${\delta}^{13}C$ and ${\delta}^{18}O$ values were determined for the Paleozoic limestones (Great Linestone Series) from the Taebaegsan region and the age-unknown limestones (Janggun Formation) from the Janggun mine, Korea. Limestones of the Great Limestone Series exhibit a range of carbon isotopic composition from -4.5 +1.3‰ with a mean ${\delta}^{13}C$ value of -1.1‰, relative to the PDB standard, and of oxygen isotpic composition from +8.8 to +23.3‰ with a mean ${\delta}^{18}O$ value of +16.0‰, relative to the SMOW, falling into the normal marine limestone range according to Keith and Weber (1964), and Degens and Epstein(1964). Carbon isotopic composition of limestones of the Great Limestone Series becomes progressively lighter from Pungchon limestone of middle Cambrian age to mid-Ordovician Maggol limestone, possibly due to change in depositional environment in the Taebaegsan basin. Variation in isotopic composition of limestones from Hwajeol to Dumugal formation offers the possibility or deposition in shallow sea environment, in which fresh waters were added in several stages. Janggun limestone of unknown age may be corelated with the Paleozoic limestones of Great Limestone Series as infered from the istopic composition ranging from -2.8 to + 0.7‰ of ${\delta}^{13}C$ and +13.4 to +22.4‰ of ${\delta}^{18}O$.