• Journal of Astronomy and Space Sciences
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• 제34권4호
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• pp.331-342
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• 2017

To ensure the successful launch of the Korea pathfinder lunar orbiter (KPLO) mission, the Korea Aerospace Research Institute (KARI) is now performing extensive trajectory design and analysis studies. From the trajectory design perspective, it is crucial to prepare contingency trajectory options for the failure of the first lunar brake or the failure of the first lunar orbit insertion (LOI) maneuver. As part of the early phase trajectory design and analysis activities, the required time of flight (TOF) and associated delta-V magnitudes for each recovery maneuver (RM) to recover the KPLO mission trajectory are analyzed. There are two typical trajectory recovery options, direct recovery and low energy recovery. The current work is focused on the direct recovery option. Results indicate that a quicker execution of the first RM after the failure of the first LOI plays a significant role in saving the magnitudes of the RMs. Under the conditions of the extremely tight delta-V budget that is currently allocated for the KPLO mission, it is found that the recovery of the KPLO without altering the originally planned mission orbit (a 100 km circular orbit) cannot be achieved via direct recovery options. However, feasible recovery options are suggested within the boundaries of the currently planned delta-V budget. By changing the shape and orientation of the recovered final mission orbit, it is expected that the KPLO mission may partially pursue its scientific mission after successful recovery, though it will be limited.

• Nuclear Engineering and Technology
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• 제45권4호
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• pp.427-438
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• 2013

In this paper we discuss spent fuel management options in the Republic of Korea (ROK) from two interrelated perspectives: Centralized dry cask storage and spent fuel pyroprocessing and burning in sodium fast reactors (SFRs). We argue that the ROK will run out of space for at-reactors spent fuel storage by about the year 2030 and will thus need to transition centralized dry cask storage. Pyroprocessing plant capacity, even if approved and successfully licensed and constructed by that time, will not suffice to handle all the spent fuel discharged annually. Hence centralized dry cask storage will be required even if the pyroprocessing option is successfully developed by 2030. Pyroprocessing is but an enabling technology on the path leading to fissile material recycling and burning in future SFRs. In this regard we discuss two SFR options under development in the U.S.: the Super Prism and the Travelling Wave Reactor (TWR). We note that the U.S. is further along in reactor development than the ROK. The ROK though has acquired more experience, recently in investigating fuel recycling options for SFRs. We thus call for two complementary joint R&D project to be conducted by U.S. and ROK scientists. One leading to the development of a demonstration centralized away-fromreactors spent fuel storage facility. The other involve further R&D on a combined SFR-fuel cycle complex based on the reactor and fuel cycle options discussed in the paper.

• Journal of Nutrition and Health
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• 제56권1호
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• pp.112-121
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• 2023

Purpose: Eating behaviors are influenced by food environments, such as availability and/or accessibility of healthy food options. In this study, we examined the relationship between healthy eating-out options and the intention to eat healthily in adults residing in Daqing, China, using an extended theory of planned behavior (TPB). Methods: Data were collected via an online survey conducted from April to May 2021 using a previously validated questionnaire in Daqing. A total number of 308 subjects aged 18-64, either Daqing oilfield workers or their family members were eligible and finally included in the analysis. The relationships among the attributes and the quality of healthy eating-out options, the three major constructs of TPB, and the intentions of healthy eating were examined using multiple linear regression analyses. Results: Subjective norms (p = 0.049) and perceived behavioral control (PBC) (p = 0.000) were significantly related to the healthy eating intention. The quality and attributes of the food served statistically significantly explained the intention to eat healthily. After controlling for age, sex, and body mass index, not the quality but the attributes of food served (p = 0.037), subjective norms (p = 0.016), and PBC (p = 0.000) had a significant relationship with the intention to eat healthily. The model explained 83.7% of the variance. Conclusion: The healthy eating-out choices, along with subjective norms and PBC of TPB, may be a potential determinant of healthy eating intention among Chinese adults living in Daqing, China. Policy implications have highlighted that not only the personal intention to eat healthy foods, but also the available healthy food environment may be important for the choice of healthy options by the population of interest. Therefore, building an environment for healthy eating choices and campaigns aimed at increasing consumer awareness of healthy eating are equally important for a smart eating choice.

• 대한산업공학회지
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• 제29권2호
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• pp.126-134
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• 2003

Among a variety of models proposed by so far to calculate the real options value when the investment decision about the underlying project may be delayed, the Black-Scholes and the binomial lattice models have been widely used and discussed by academics and practitioners. However these two models do not provide us with intuition into how it is constructed and what it does really mean. In this paper, we will therefore explore its components and practically more intuitive meaning. With the components explored, we developed the mathematical model to calculate the real options value and thus strategic net present value, based on the opportunity cost concept, for which the investment decision about the underlying project is postponed by one year. We will finally present a short illustrative example for readers better understanding on the model proposed in the paper.

• 대한산업공학회지
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• 제38권4호
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• pp.244-248
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• 2012

We present a simple numerical method for pricing American put options under a constant elasticity of variance (CEV) model. Our analysis is done in a general framework where only the risk-neutral transition density of the underlying asset price is given. We obtain an integral equation of early exercise premium. By exploiting a modification of the integral equation, we propose a novel and simple numerical iterative valuation method for American put options.

• 응용통계연구
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• 제22권1호
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• pp.59-73
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• 2009

A floating-strike lookback call option gives the holder the right to buy at the lowest price of the underlying asset. Similarly, a floating-strike lookback put option gives the holder the right to sell at the highest price. This paper will propose an outside floating-strike lookback call (or put) option that gives the holder the right to buy (or sell) one underlying asset at some percentage of the lowest (or highest) price of the other underlying asset. In addition, this paper will derive explicit pricing formulas for these outside floating-strike lookback options. Sections 3 and 4 assume that the underlying assets pay no dividends. In contrast, Section 5 will derive explicit pricing formulas for these options when their underlying assets pay dividends continuously at a rate proportional to their prices. Some numerical examples will be discussed.

• 한국경영과학회지
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• 제32권1호
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• pp.15-26
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• 2007

This study analyzes revenue-maximizing strategies of online auction sellers in terms of setting up starting bids and buy-it-now options. To this end, a series of field experiments is conducted where women's hair accessories of unique designs are listed in an established online auction site. The results of the experiments argue that high starting bids could increase sellers' revenue while buy-it-now options have no significant effects. Our findings suggest that online auction sellers listing items with uncertain demand - mainly individual sellers - should be cautious with auction tips which generally support low starting buds.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.689-699
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• 2020

In this work, new multi-recycling options of TRU nuclides using PWR fuel assemblies comprised of MOX and FCM (Fully Ceramic Micro Encapsulated) fuels are suggested and neutronically analyzed. These options do not use a fully recycling of TRU but a partial recycling where TRUs from MOX fuels are recycled while the ones from FCM fuels are not recycled due to their high consumption rate resulted from high burnup. In particular, additional external TRU feed in MOX fuels for each cycle was considered to significantly increase the TRU consumption rate and the finally selected option is to use external TRU and enriched uranium feed as a makeup for the heavy metal consumption in MOX fuels. This hybrid external feeding of TRU and enriched uranium in MOX fuel was shown to be very effective in significantly increasing TRU consumption rate, maintaining long cycle length, and achieving negative void reactivity worth during recycling.

• KDI Journal of Economic Policy
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• 제23권1_2호
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• pp.149-191
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• 2001

In this paper, we propose a new bankruptcy algorithm. The proposed algorithm is comprised of four tasks. Task A is the procedure of soliciting bids, Task B is the procedure of allocating claims, Task C is the procedure of trading claims, and Task D is the procedure of exercising options and holding shareholders' meeting. Tasks A, B, and D are based on Bebchuk(1988) and Aghion, Hart, ad Moore(1992). This paper adds Task C, the procedure of trading claims. Claims are in the form of options which are written on the new shares of the bankrupt firm. Trading options expedites the process of finding the value of the bankrupt firm, and also it mitigates the problem of incomplete capital market by expanding the pool of new investors.

• Nuclear Engineering and Technology
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• 제29권4호
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• pp.348-359
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• 1997

This paper reviews cooling aspects of the diverter system in Tokamak fusion devices with primary emphasis on the critical heat flux (CHF) issues for oater-cooled designs. General characteristics of four (4) coolant options for diverter cooling gases, oater, liquid metal, and organic liquid - are discussed first, focusing on the comparison of advantages and disadvantages of those options. Then results of recent studies on the high-heat-flux CHF of water at subcooled high-velocity conditions are reviewed to provide a general idea on the feasibility of the water-cooled diverter concept for future Tokamak fusion reactors. Water is assessed to be the most viable and practical coolant option for diverters of future experimental Tokamaks.