• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.441-464
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• 2012

As prices of energy resources such as oil and gas started to rise steadily in 2000, energy security has been one of the most important topics in the world. To secure more energy, most of countries which are highly dependent on imported energy resources try to occupy oversea oil or gas reserves, thereby intensifying competition for energy resources around world. Under this circumstance, we focus on independent E&P companies since they are relatively small size companies which are suitable for M&A. We analyze investment option values for these E&P companies using a real option model for depletable resources. Based on analytical model, empirical study is provided to examine rationality of investment for energy companies. The result shows sufficient profitability for independent E&P companies in both oil and gas projects in the North America during 2004 to 2008. In Particular, oil projects were more feasible than gas project due to lower price of gas and high volatility of gas price at that time.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.10a
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• pp.3-8
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• 1998

The present work proposes the potential fuzzy framework, based on fuzzy set theory, for supporting decision-making problems, especially, selection problems of a best design in the area of nuclear energy system. The framework proposed is composed of the hierarchical structure module, the assignment module, the fuzzification module, and the defuzzification module. In the structure module, the relationship among decision objectives, decision criteria, decision sub-criteria, and decision alternatives is hierarchically structured. In the assignment module, linguistic or rank scoring approach can be used to assign subjective and/or vague values to the decision analyst's judgment on decision variables. In the fuzzification module, fuzzy numbers are assigned to these values of decision variables. Using fuzzy arithmetic operations, for each alternative, fuzzy preference index as a fuzzy synthesis measure is obtained. In the defuzzification module, using one of methods ranking fuzzy numbers, these indices are defuzzified to overall utility values as a cardinality measure determining final scores. According these values, alternatives of interest are ranked and an optimal alternative is chosen. To illustrate the applicability of the framework proposed to selection problem, as a case example, the best option choice of four design options under five decision criteria for primary containment wall thickening around large penetrations in an advanced nuclear energy system is studied.

• Steel and Composite Structures
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• v.12 no.3
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• pp.249-260
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• 2012

In this study, stress and deflection behaviours of T-type welding joint applied to HE200M steel beam and column were investigated in finite element method (FEM) under different distributed loads. In the 3D-FEM modelling, glue option was used to contact between steel materials and weld nuggets. Geometrical model was designed as 3-dimensional solid in ANSYS software program. After that, homogeneous, linear and isotropic properties were used to design to materials of model. Solid-92 having 3-dimensional, 4 faced and 10-noded was selected as element type. In consequence of mesh operation, elements of 13285 and nodes of 28086 were occurred. Load distribution was applied to top surface of steel beam to determine behaviours of stress and deflection. As a result of FEM analysis applied with the loads of 55,000 N, 110,000 N and 220,000 N, maximum values were obtained as 116 N/$mm^2$, 232 N/$mm^2$ and 465 N/$mm^2$ for stress and obtainedas 1,083 mm, 2,166 mm and 4.332 mm for deflection, respectively. When modelling results and classical calculation values were compared, it was obtained difference of 10 % for stress values and 2.5% for deflection values.

• Journal of Environmental Science International
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• v.31 no.8
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• pp.727-733
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• 2022

The contingent valuation method (CVM) is one of the most commonly used and effective methods to evaluate non-use value of resources. Reasonable application of CVM to value the cultural heritage is the key process of evaluation. CVM was used to evaluate the non-use value of cultural heritage of Taishan Mountain combined with questionnaire survey and field research in this study. The results indicated that the importance of the degree of the three components of non-use value was heritage value ranked highest (40.22%) > followed by existence value (38.58%) >then option value (21.20%). In addition, the rate of willingness to pay was 54.52%, the average and median values of per person were 40.17 CNY·a^-1 and 20.00 CNY·a^-1 and the non-use values of Taishan Mountain cultural heritage was 33 million CNY·a^-1. The median value of WTP was consistent with Asian countries but was lower than European and American countries. Factors influencing WTP showed that monthly income and satisfaction with Taishan Mountain were correlated to WTP, and family location and willingness to revist were correlated remarkably with WTP. In addition, monthly income was correlated remarkably with WTP value, however other factors were not. The results showed the importance and necessity of protective development of Taishan Mountain cultural heritage, which would be used as an important reference for decision makers.

• Toxicological Research
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• v.29 no.2
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• pp.99-106
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• 2013

Clostridium difficile infection (CDI) has become a significant threat to public health. Although broad-spectrum antibiotic therapy is the primary treatment option for CDI, its use has evident limitations. Probiotics have been proved to be effective in the treatment of CDI and are a promising therapeutic option for CDI. In this study, 4 strains of lactic acid bacteria (LAB), namely, Lactobacillus rhamnosus (LR5), Lactococcuslactis (SL3), Bifidobacterium breve (BR3), and Bifidobacterium lactis (BL3) were evaluated for their anti-C. difficile activity. Co-culture incubation of C. difficile ($10^6$ and $10^{10}$ CFU/ml) with each strain of LAB indicated that SL3 possessed the highest antimicrobial activity over a 24-hr period. The cell-free supernatants of the 4 LAB strains exhibited $MIC_{50}$ values between 0.424 mg/ml (SL3) and 1.318 (BR3) mg/ml. These results may provide a basis for alternative therapies for the treatment of C. difficile-associated gut disorders.

• Korean Management Science Review
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• v.31 no.2
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• pp.71-86
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• 2014

There is a growing need for technology transactions between the technology providers, who develop technologies, and the technology consumers, who purchase and commercialize technologies, to be smooth, when technologies, as intangible assets, are traded as items that can be purchased and sold. In response to these challenges, this study examines new approaches to assessing the fair market value of technologies. Because corporations are the main force behind technology development and commercialization in the existing business environment, applying one valuation method to technology assets is viable; however, as the subjects of technology development and technology commercialization are separate, the need for price negotiations between the subjects of technology transaction has grown. Moreover, as the investigations into and the application of transaction prices have been performed separately by technology providers, technology consumers, and technology assessment financial institutions, the research on technology valuation methods has shown that there are differences in perceived transaction prices between the subjects involved. This research presents a new method, appropriate to technology transactions; unlike existing methods, it grants option values to the technology provider and newly defined key variables to the technology consumer.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.8-15
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• 2021

Vegetarians have claimed and actively promoted the advantages of plant-based alternative milks as the best option for human nutrition and health, compared to the natural dairy milk. However, numerous scientific evidences and reports have demonstrated that the natural milk possesses more beneficial nutrients and bioactive components than artificially manufactured plant-derived milks. The biochemical and nutritional advantages and functionalities of natural dairy milk cannot be replaced by man-made or crafted plant-based beverage products. On the other hand, the tremendous increase in production and consumption of the plant-based alternative milks in recent years has led a serious business downturn in traditional roles and stability of the dairy industry, especially in the major dairy producing Western countries. Although plant-based milk alternatives may have some benefits on nutrition and health of certain consumers, the plant-derived alternative milks may not overshadow the true values of natural milk. Milk is not a high fat and high cholesterol food as animal meat products. Unlike plant-based alternative milks, natural milk contains many bioactive as well as antiappetizing peptides, which can reduce body weight. It has proven that taking low-fat, cultured and lactase treated milk and dairy products with other diversified nutritionally balanced diets have been shown to be healthier dietary option than plant-based milk/foods alone.

• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.465-491
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• 2012

Climate change, a result of increasing global warming, has been receiving more public attention due to its serious impact upon many industries. In this study we consider sustainable- (Green-) Growth and Green-Finance, and in particular temperature derivatives, as appropriately active responses to the world's significant climate change trends. We characterize the daily average temperatures in Seoul, South Korea with their seasonal properties and cycles of error terms. We form forecasting models and perform Monte Carlo simulations, and find that the risk-neutral values for CDD call-options and HDD put-options have risen since 1960s, which implies that the trend of temperature increase can be quantified in the financial markets. Contrary to the existing models, the Vasicek model with the explicit consideration of cycles in the error terms suggests that the significant option-values for the CDD call -options above certain exercise prices, implying that there is the possibility of explicit hedging against the considerable and stable increase in temperature.

• Korean Journal of Construction Engineering and Management
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• v.18 no.2
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• pp.81-90
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• 2017

In Imjin River basin, three floods occurred between 1996 and 1999, causing many casualties and economic losses of 900 billion won. In Korea, flood damage is expected to increase in the future due to climate change. This study used the climate scenarios to estimate future flood damage costs and suggested a real options-based economic assessment method. Using proposed method, the flood control infrastructures in Imjin River basin were selected as a case study site to analyze the economic feasibility of the investment. Using RCP (Representative Concentration Pathway) climate scenarios, the future flood damage costs were estimated through simulated rainfall data. This study analyzed the flood reduction benefits through investment in the flood control infrastructures. The volatility of flood damage reduction benefits were estimated assuming that the RCP8.5 and RCP4.5 climate scenarios would be realized in the future. In 2071, the project option value would be determined by applying an extension option to invest in an upgrading that would allow the project to adapt to the flood of the 200-year return period. The results of the option values show that the two investment scenarios are economically feasible and the project under RCP8.5 climate scenario has more flood damage reduction benefits than RCP4.5. This study will help government decision makers to consider the uncertainty of climate change in the economic assessment of flood control infrastructures using real options analysis. We also proposed a method to quantify climate risk factors into economic values by using rainfall data provided by climate scenarios.

• Journal of Astronomy and Space Sciences
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• v.37 no.1
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• pp.1-9
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• 2020

Frozen orbit is an attractive option for orbital design owing to its characteristics (its argument of pericenter and eccentricity are kept constant on an average). Solar sails are attractive solutions for massive and expensive missions. However, the solar radiation pressure effect represents an additional force on the solar sail that may greatly affect its orbital behavior in the long run. Thus, this force must be included as a perturbation force in the dynamical model for more accuracy. This study shows the calculations of initial conditions for a lunar solar sail frozen orbit. The disturbing function of the problem was developed to include the lunar gravitational field that is characterized by uneven mass distribution, third body perturbation, and the effect of solar radiation. An averaging technique was used to reduce the dynamical problem to a long period system. Lagrange planetary equations were utilized to formulate the rate of change of the argument of pericenter and eccentricity. Using the reduced system, frozen orbits for the Moon sail orbiter were constructed. The resulting frozen orbits are shown by two 3Dsurface (semi-major, eccentricity, inclination) figures. To simplify the analysis, we showed inclination-eccentricity contours for different values of semi-major axis, argument of pericenter, and values of sail lightness number.