• Journal of the Korean Medical Association
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• v.61 no.11
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• pp.644-648
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• 2018

The incidence of skin cancer has continuously increased in Korea, probably due to sun exposure and increases in the aging population. Ultraviolet light, a well-known risk factor for skin cancer, can cause DNA damage, mutation, and immune suppression, followed by abnormal proliferation. To prevent photocarcinogenesis, the appropriate use of sunscreen should be emphasized. Using broad-spectrum sunscreens with sun protection factor values of 15 or higher and frequent reapplication are recommended. Controversy exists about whether vitamin D synthesis is inhibited by the use of sunscreen. However, considering that skin cancer most commonly develops on the head and neck area, applying it to the face and neck is reasonable in terms of balancing the risk-benefit ratio.

• The Journal of Fisheries Business Administration
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• v.53 no.2
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• pp.1-20
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• 2022

This study is aimed to analyze fishermen's perception and the economic feasibility of inland waters ranching project on the branches of Geum River. Analysis of fishermen's perception on the branches of Geum River showed that fishermen had an affirmative response on the inland freshwater ranching project related issues such as fisheries resources enhancement, necessity of project, economic achievement as so on. The model of inland waters ranching project on the branches of Geum River is designed to fisheries resources enhancement, habitat compositiom, ecology tours, use and management of resources. The results of the economic feasibility of inland waters ranching project on the branches of Geum River were internal rate of return (IRR) was 18.43%, a benefit-cost ratio was shown to be 1.54, net present value (NPV) was 4,929 thousand won, which indicates the economic feasibility of inland waters ranching project.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.73-75
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• 2014

Marine transportation facility is public goods for the general public and their safety. The study used the Contingent Valuation Method (CVM), a method to estimate economic value of non-market goods, such as environmental goods. In order to analyze economic effects of marine accidents preventable by the VTS, the study estimated costs caused by marine accident cases. It conducted surveys with people and shipping companies in local areas where VTS is to be established in the future. According to a survey with people in areas where marine transportation control center is to be built (Tongyoung), the yearly benefit from building new VTS is estimated at KRW 11billion. If fees are paid in the form of income tax for five years from 2014, corresponding benefits during the same period will reach KRW 47.3 billion in current value. An analysis on economic validity of VTS establishment in Tongyong showed the B/C ration stood at 3.193, far higher than 1. The Net Present Value (NPV) was KRW 32.5 billion and the Internal Rate of Return (IRR) turned out to be 37.4% which was higher than social discount rates of 53.5%. On balance, the establishment has reasonable economic validity.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.24-29
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• 2013

This study was carried out for preliminary feasibility review to investigate work efficiency of chestnut harvest using yield net and to find a way to reduce the cost for purchasing and managing yield net. To this end, we conducted a survey of 6 forest farm houses in Cheongyang, Gongju and Buyeo regions where yield nets are being used efficiently. Cost-benefit analysis based on Net Present Value and Benefit Cost Ratio was used to examine the investment profitability. While regions of Cheongyang A, Cheongyang B and Buyeo A are profitable in spite of no subsidy for purchasing yield net from the government, the regions of Gongju A, Gongju B and Buyeo B are not profitable without subsidy. When an 80% of subsidy for purchasing yield nets is provided, the forest farm houses in Cheongyang A, Cheongyang B, Buyeo A and Gongju B regions are found to be profitable while those in Gongju A and Buyeo B regions are still not profitable. We consider that the different results come from the differences in the planting method of chestnut, labor efficiency, labor skill and the orchard conditions such as slop. Finally, several efforts for government and cultivator are suggested to expand the use of yield net; planting chestnut in line, establishing installation and management methods, supporting the cost for purchasing yield net and studying detailed effects besides profitability issue.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.326-332
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• 2018

Korea faces major changes in energy policy, which include eco-friendly and zero-nuclear power. On the other hand, there are very few policies for the waste-management of mid- to large-sized lithium-ion batteries, such as electric car batteries and energy storage systems, which are expected to increase explosively due to such energy policy changes. Therefore, this study estimated the amount of mid- to large-sized lithium ion batteries waste and performed economics analysis of a middle and large sized secondary battery recycling project. Based on the results, a policy alternative for the revitalization of the related lithium-ion battery recycling industry is suggested. As a result, the B / C ratio of a domestic mid - to large - sized lithium ion battery recycling project is 1.06, in which the benefit is higher than the cost, so the business is economic feasible. Although the recycling project's economic efficiency is high, the recycling industry has not been activated in Korea because the domestic demand for rechargeable batteries recycling is very low. To solve this problem, this study proposes a plan to activate the industry by adding lithium secondary batteries to the EPR (Extended Producer Responsibility) items.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.19-32
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• 2016

Due to the increasing fiscal burden and structural unbalanced premium/benefit costs, the new reform on the government employees pension system (GEPS) was considered even after the recent reform in 2009. This article examines the various effects of recent amendment in 2015 on GEPS using a simple probabilistic model. We consider effects on both sides, the pensioners and the government. First of all, the expected net value of pension payment for an individual employee was calculated based on the supposed survival distribution. The fairness of individual pension holders was compared using the benefit-cost ratio. Secondly, from pension system users' point of view, the default probability and the government subsidy were examined by Monte-carlo simulation. From the simulation experiment, we could see that the 2015 reform plan indeed reduces the default probability and the size of the fiscal burden of government by increasing the premium and decreasing the benefit. However, the size of the effect is not very standout at this moment because the number of new employees who are fully subject to the reform will be much smaller than the number of previous employees for a while. Thus, the effect of the reform is expected to appear in a slow manner.

• Journal of Energy Engineering
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• v.22 no.3
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• pp.270-282
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• 2013

Combustible waste into energy policy is an effective method to respond to climate change and depletion of fossil fuels. Combustible waste into energy is the process of generating energy in the form of electricity and/or heat from the combustible waste such as vinyl, paper and plastic. This study tries to estimate the external benefit of enhancing the ratio of combustible waste into energy to primary energy from 1.89% to 5% using contingent valuation(CV) method. To this end, we report the results from a CV survey to elicit the willingness to pay (WTP) for combustible waste into energy. A CV survey of 500 households was conducted in the Seoul by using person-to-person interviews. Thus, the procedures of applying and the findings from the one-and-one-half bounded dichotomous choice spike model used to deal with the zero WTP responses are provided in the paper. The results show that the average WTP is estimated to be 2,724 won per household per month and statistically significant at the 5% level. Expanding the value to the Seoul gives us an aggregate value of 13.7 billion won per year.

• Resources Recycling
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• v.32 no.3
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• pp.45-56
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• 2023

This study analyzed the economic and environmental effect of recycling rhodium used in the non-catalytic field. As an analysis methodology, economic effect analysis applied cost-benefit analysis and resource-saving effect analysis and the environmental effect analysis applied life cycle assessment (LCA). The results show that from an economic point of view, the cost-benefit ratio was 1.28, which was feasible, and the cost reduction was 237,000 won based on 1 g of rhodium recycled and the amount of rhodium recycled was 7.17 billion won in 2025. As for the environmental effect, the greenhouse gas(GHG) emissions were compared between the case of recycling based on rhodium 1 kg and the case of overseas sales. The calculation results show that based on rhodium 1 kg, greenhouse gas emissions were reduced by 99.8%, from 65 kg CO₂eq./kg-Rh when recycling to 28,800 kg CO₂eq. when sold overseas. The results obtained from this study could suggest that rhodium recycling is necessary in Korea where resources are scarce by analyzing the economic and environmental effect of recycling rhodium used in the non-catalytic field.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.11-19
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• 2015

The important properties of EVA (ethylene vinyl acetate) redispersible polymer was waterproof, densification of internal pore space of concrete and ball bearing and micro filler. Also, the significant role of polypropylene(PP) fiber was crack control and blockade of movement for deterioration factors. The most studies for EVA were limited in the field of mortar and PP fiber reinforced concrete had been studied in the state of being restricted unit water content, rich mix and mixing much of the fiber without considering construction site. Therefore, the control mix design were applied in ready mixed concrete using 10 % fly ash of total cement weight used in batch plant. On the basis of control mix design, EVA contents ranging from 0 % to 10 % of total cement weight and PP fiber contents ranging from 0 % to 0.5 % of EVA concrete volume were used in the mix designs. The results showed the maximum compressive strength value was measured at EVA 5.0 % and PP fiber 0.1 %, the minimum water absorption ratio was at EVA 10 % and PP fiber 0 %, the durability factor for freezing and thawing resistance was at EVA 5.0 % and PP fiber 0.3 % and the minimum weight reduction ratio of resistance to sulfuric acid attack was at EVA 10 % and PP fiber 0.5 % after curing age 42days. Meanwhile, From these results, PP fiber reinforced EVA concrete would be very benefit, if each optimal mix types were used in hydraulic structures, underground utilities and agricultural structures.

• Journal of Biomedical Engineering Research
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• v.32 no.1
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• pp.45-54
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• 2011

Cuff electrodes have a benefit for chronic electroneurogram(ENG) recording while minimizing nerve damage. However, the ENG signals are usually contaminated by electromyogram(EMG) activity from the surrounding muscle, the thermal noise generated within the source resistance, and the electric noise generated primarily at the first stage of the amplifier. This paper proposes a new cuff electrode to reduce the interference of EMG signals. An additional middle electrode was placed at the center of cuff electrode. As a result, the proposed cuff electrode achieved a higher signal-to-interference ratio compared to the conventional tripolar cuff. The cuff electrode was then assembled together with closure, headstage, and hermetic case including electronic circuits. This paper also presents a lownoise amplifier system to improve signal-to-noise ratio. The circuit was designed based on the noise analysis to minimize the electronic noise. The result shows that the total noise of the amplifier was below $1{\mu}V_{rms}$ for a cuff impedance of $1\;k{\Omega}$ and the common-mode rejection ratio was 115 dB at 1 kHz. In the current study, the performance of nerve cuff electrode system was evaluated by monitoring afferent nerve signals under mechanical stimuli in a rat animal model.