• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.627-635
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• 2016

Recently, several construction projects have been built to create residential area, industrial complex and agricultural land on reclaimed on- and offshore regions. Estimating the quantity of filling materials during reclamation is the most curcial factor of the total construction cost of reclamation project. However, the estimation of loss ratio, defined as the ratio of loss amount to overall dumped amount, mostly depends on the empirical methods and formulae based on the material characteristics due to the lack of sufficient literature about the loss ratio according to hydraulic conditions. In this studies the loss ratio of materials considering flow conditions and material characteristics were examined through hydraulic experiments. A series of hydraulic experiments was conducted using five different hydraulic conditions and two types of materials such as sand and anthracite in a horizontal rectangular flume ($13.0m{\times}5.0m{\times}0.10m$), in which a round type revetment was installed. It is found that the loss ratio generally tends to increase with increasing the particle Froude number regardless of the types of materials. Also, when the flow velocity(u) becomes higher than the critical flow velocity ($u_c$), the loss ratios of sand and anthracite are dramtically increased up to 7.4% and 24.4%, respectively. As a future work, more specific mean velocities will be considered to figure out the loss ratio and more accurate estimation of amount of filling materials will be possible to present with confidence.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.19-24
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• 2020

The interest in renewable energy is increasing due to the depletion of fossil fuels. In particular, active research on wave power, which is highly predictable and abundant, is being conducted. The coaxial accelerator-type wave power generator used in this study was designed to improve the power generation efficiency by converting bidirectional linear motion into a rotational force. In an offshore engineering basin, waves were generated, and case tests were performed according to the wave period and wave height. The experimental results were verified by the theoretical method related to the frequency response, and the overall trend was confirmed to be consistent. These results are expected to be useful in estimating the power of wave generators and designing parameters to improve the efficiency of wave energy in the design stage before manufacturing. In addition, the manufacturer can predict the wave energy efficiency of wave generators, which can reduce the development time and cost by preventing trial and error processes.

• Environmental and Resource Economics Review
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• v.17 no.4
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• pp.845-873
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• 2008

This study estimates the VSL(value of a statistical life) as well as the WTP(willingness to pay) for mortality risk reduction using sample selection model with data on liver cancer examination which is associated with little possibility of multi-purpose(i.e. joint production) in averting behavior. The marginal benefits of mortality risk reduction are estimated by applying for household production function model with medical expense and the time required for medical examination of liver cancer. Individuals are more likely to take liver cancer test if they are male, older, higher educated, those with spouse, smoker, more income of household, and more anxious about their health. The costs of liver cancer examination are statistically significantly affected with expected signs by size of mortality risk reduction, sex, period of eduction, those with spouse, and household income. The marginal effect of mortality risk reduction owing to taking liver cancer examination is estimated at 321,097 won. The costs of liver cancer examination are increased by 905 won with more one year of education period and by 1,743 won with more one million won in household income. On liver cancer examination, male spends more 12,310 won than female and those with spouse pay more 7,969 won than those without spouse. Therefore the VSL from mortality risk reduction due to liver cancer examination is 321.10 million won at mean size of mortality risk reduction and mean cost of liver cancer examination. The results of sensitivity tests on costs and effects of liver cancer test shows that the VSLs are estimated in a range from 160.55 million won to 642.19 million won.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.965-972
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• 2016

This paper presents results of flight experiments on a navigation algorithm including multiplicative extended Kalman filter for estimating attitude of the guided munition. The filter describes orientation of aircraft by data fusion with low-cost sensors where measurement update is done by multiplication, rather than addition, which is suitable for quaternion representation. In determining attitude from vector observations, the existing approach utilizes a 3-axis accelerometer as a 2-axis inclinometer by measuring gravity to estimate pitch and roll angles, while GNSS velocity is used to derive heading of the vehicle. However, during accelerated maneuvers such as coordinated flight, the accelerometer provides inadequate inclinometer measurements. In this paper, the measurement update process is newly defined to complement the vulnerability by using different vector observations. The acceleration measurement is considered as a result of a centrifugal force and gravity during turning maneuvers and used to estimate roll angle. The effectiveness of the proposed method is verified through flight experiments.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.421-433
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• 2016

Recently, although the interest in transfer and transactions of intangible assets increases, there is no valuation model to objectively assess market value of knowledge and information contents such as electronic databases and the necessity of researches associated is brought up. Therefore, the present study proposes valuation models so as to utilize as objective reference information in the contents market of intangible assets, by assessing the market value of science and technology information contents including patents, academic papers and reports. First, we look into application methods of calculating cash flows by content types out of key variables which has been applied to the present technology valuation, and in case of patents we propose valuation methods based on concepts which are applied in the present technology valuation. Next, in case of both papers and reports, in order to reflect the characteristics of these contents we newly propose qualitative valuation methods which are adjustable based on both technology innovation and market demands indices while estimating the economic life cycle of the technology, and also present the input cost-based calculation method as the calculation method of cash flows. Throughout the study, we could establish frameworks by technology fields and business models applicable such as copyright licensing, transactions of individual science and technology information contents, and expect that more objective and reasonable assessment of content values is accessible.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.234-244
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• 2007

Both competent authorities and private entrepreneurs face plenty of risks when negotiating BTO(Build Transfer Operation) methods of PPI(Private Participations in Infrastructures) projects. Also, success and failure of projects largely depend on the concession agreement contract. In this study, for more efficient negotiation, major issues are examined, and quantitatively analyzed to find out not only the relationship but also the characteristics of which these issues share. Questionnaire research was conducted through both research and by experts who were divided into an ordering agency, design company and constructor. Characteristics of major issues were quantitatively analyzed using the Likert index method, ANOVA(ANalysis of VAriance) and AHP(Analytic Hierarchy Process) analysis. Case studies were examined in order to estimate construction cost, rates of return, government finance support, level of operation-revenues guarantees, estimating operational costs and usage fees. With these 6 items, relative priority, relative impression which is sensible to risk and extent of difficulty in presenting data which is objective were quantitatively analyzed by the ordering agency, design company and constructor groups. From the analysis, there were some similarities between the design company and constructor groups while there was less of similarities between the ordering agency and design company or constructor. The government is diversifying the methods of project promotion, and PPI project from infrastructure-centered to public culture facilities are being expand. The current study will provide not only supporting efficient negotiation but also revitalizing PPI projects.

• Journal of Korea Technology Innovation Society
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• v.10 no.1
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• pp.1-21
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• 2007

Among numerous policy influencers' and researchers' advices and policy suggestions, there is little opposition to the proposition that technology is essential to the economic development. The role of technology has never been more emphasized than today in Korea as in any other countries. The effects of the government's innovation policy on corporate R&D activities and more broadly the economic welfare of a whole nation are widely recognized with intuitional and empirical evidence. That is, various R&D incentives reduce the marginal cost of a firm's R&D efforts, inducing as much increase of its R&D investment to result in a better chance to acquire target technology. This paper examines the impact of R&D incentives on the technological outcomes by analyzing individual firms' investment behaviors subject to the government's R&D incentive policies. An econometric model of technological outcomes is estimated on a project level with cross-sectional data. "Probit model" is employed for estimations. Special attention was given to the effectiveness of R&D programs by estimating policy impact by types of investment. The data were collected from 928 different R&D projects completed between 1987 and 1993. With the single equation approach, we were able to find that the structure of investment is a far more significant factor in technological outcomes than the total amount of investment. The analysis also shows that the two types of firms' matching investment, in-kind and cash, do not bear a complementary, but a substitutive relations to each other. It also reconfirms the proposition that R&D incentives increase firm's financial investment. Despite many supportive studies emphasizing the cooperation between innovation performers, it is also found that the larger the number of institutions involved in a project, the less likely it leads to a technological success, And meeting the proposed deadlines without postponing is estimated to be a good barometer to predict the outcome of an R&D project. Also the probabilities of success for major variables are represented for policy implications, after calculating marginal effects.

• Management & Information Systems Review
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• v.28 no.1
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• pp.71-97
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• 2009

In this study, I compare the ability of alternative accounting method for employee stock option to reflect firm value using the Ohlson's(1995) valuation model for 200 firms. The each methods, I compare are employee stock option expense recognition based on the K-GAAP disclosures, and asset recognition at the grant date based on the SFAS No. 123 Exposure Draft: Accounting for stock-based compensation. The model include: (1) a model that uses reported earnings, equity book value, and compensation expense based on the K-GAAP disclosures; (2) a model that uses pro-forma earnings, equity book value and adds a measure of the unrecognized asset arising form granting of employee stock options. Finding form estimating equations that the K-GAAP method for calculating compensation has no explanatory power, and the SFAS No.123 Draft Exposure method for arising asset and fair value compensation better captures than market's perception of the economic impact of stock options on firm values. However, the correlation of employee stock option compensation expense is positive. These results suggest that incentive benefits derived from employee stock option plans outweigh the cost associated with plan. In addition, I couldn't find evidence that company in KOSDAQ that have high growth potential benefit more from employee stock option plan compared to lager, more mature firm in SEC.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.221-229
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• 2015

This study aims to identify and analyze the main factors that determine the properties and buying behavior in the premium bottled select and analyze the degree of impact on the relevant variables are premium water demand. When applied to the truncated negative binomial model to derive the study results: The results of estimating the variables that affect the demand for premium mineral water are as follows. Premium bottled water demand of this group my purchases with a choice between buying behavior variables are significantly higher than the relative population. To also do a good ingredient water, it appeared to be on a statistically significant positive effect on the demand for the more groups you purchase a premium bottled water for the purpose of receiving special feeling, just buy purpose is called to drinking water does not significantly affect to be analyzed. Among demographic characteristics it showed that demand for premium bottled water purchases are significantly higher in women than in men, professional / clerical job, such as the military, college graduates were more consumer research as significant in comparison to the relative population. Taste and package design factors of premium bottled mineral water among the select attribute factors are having a significant positive impact on the purchasing demand, local conditions and cost factors have been estimated to be insignificant.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.137-146
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• 2008

Both competent authorities and private entrepreneurs face plenty of risks when negotiating BTO(Build Transfer Operation) methods of PPI(Private Participations in Infrastructures) projects. Also, success and failure of projects largely depend on the concession agreement contract. In this study, for more efficient negotiation, major issues are examined, and quantitatively analyzed to find out not only the relationship but also the characteristics of which these issues share. Questionnaire research was conducted through both research and by experts who were divided into an ordering agency, design company and constructor. Characteristics of major issues were quantitatively analyzed using the Likert index method, ANOVA(ANalysis of VAriance) and AHP(Analytic Hierarchy Process) analysis. Case studies were examined in order to estimate construction cost, rates of return, government finance support, level of operation-revenues guarantees, estimating operational costs and usage fees. With these 6 items, relative priority, relative impression which is sensible to risk and extent of difficulty in presenting data which is objective were quantitatively analyzed by the ordering agency, design company and constructor groups. From the analysis, there were some similarities between the design company and constructor groups while there was less of similarities between the ordering agency and design company or constructor. The government is diversifying the methods of project promotion, and PPI project from infrastructure-centered to public culture facilities are being expand. The current study will provide not only supporting efficient negotiation but also revitalizing PPI projects.