• The Korean Journal of Quaternary Research
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• v.34 no.1
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• pp.31-40
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• 2024

The Risø Research Institute in Denmark conducted the luminescence dating intercomparison project, which derives equivalent dose, annual dose, and absolute age results for each laboratory from the same sample, and compares the results between laboratories. This project was carried out from 2006 to 2012. In this project, 30 international laboratories worldwide participated, including the luminescence laboratory at the Korea Institute of Geoscience and Mineral Resources (KIGAM). As a result of the project's synthesis, the average value of the results generally shows an over-dispersion value between laboratories of about 13%. The equivalent dose value obtained through the provided quartz analyzed in KIGAM shows results almost identical to the final equivalent dose value of the project. On the other hand, the equivalent dose value obtained from self-extracted quartz analyzed in KIGAM shows a difference of about 0.9 Gy from the final result of the project, which is thought to be due to the difference in particle size of the separated quartz. This international joint research project is the first large-scale international joint study related to luminescence dating and is expected to have contributed to the reliability and use of luminescence dating internationally.

• Journal of Korean Society for Quality Management
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• v.52 no.2
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• pp.255-274
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• 2024

Purpose: Non-Fungible Token (NFT) ART, based on NFT technology, represents a novel form of art that has recently garnered significant attention in the art market. NFT technology enables the assertion of ownership over digital data, introducing the concept of ownership into the digital realm. As digital data gains ownership, NFT ART is anticipated to be positively viewed as an investment and expected to become more active due to the characteristics of this new technology. Therefore, this study aims to verify the influence of NFT ART characteristics on perceived value. This study contributes to extracting the distinctive characteristics of NFT ART compared to other forms of art and to understanding the perceived value of NFT ART among consumers with purchasing experience. Methods: This study applied structural equation modeling to explore the relationships among the variables using SPSS 26.0 and R program version 4.2.3. A total of 320 questionnaires were retrieved, all of which were adopted as valid analytical samples without missing values. Results: The findings indicate that the decentralization, transparency, and scarcity of NFT ART positively influence the perceived usefulness and enjoyment among consumers, while security does not have a significant impact. This suggests that higher levels of decentralization, transparency, and scarcity in NFT ART enhance perceived usefulness and enjoyment for consumers, significantly influencing the perceived value. Furthermore, it was confirmed that these characteristics are considered important values and perceptions from the consumer's perspective. Conclusion: The research presents positive factors for the activating of purchases among consumers considering buying NFT ART. It emphasizes the necessity of benefits for all participants to activate the art market. Additionally, the perceived value provides crucial insights for inducing active purchasing behavior in the NFT ART market and serves as a foundational study for further research.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1708-1714
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• 2015

Fermented red ginseng concentrate is known as a healthy food source, whereas it has off-flavor such as bitterness and sour flavor based on fermentation. ${\beta}$- and ${\gamma}$-cyclodextrin (CD) were used to encapsulate the off-flavor of fermented red ginseng concentrate by using response surface methodology design on ${\beta}$- and ${\gamma}-CD$ combination. The reducing effects were analyzed by sensory evaluation for bitter and sour tastes, ginsenoside Rb1, and total acidity. The optimized mixing ratio of ${\beta}$- and ${\gamma}-CD$ for reducing bitterness was the least expected value of 2.07 at ${\beta}-CD$ 3.74% versus the soluble solid content of fermented red ginseng concentrate and the ${\gamma}-CD$ 20.63% mixture. The encapsulation effects of ginsenoside Rb1 were the most expected value of 96.75% at ${\beta}-CD$ 3.47% and ${\gamma}-CD$ 19.89% mixture. The encapsulation effects of sour taste were the least expected value of 5.63 at ${\beta}-CD$ 9.34% and ${\gamma}-CD$ 9.96% mixture. The encapsulation effects of lactic acid were the most expected value of 67.73% at ${\beta}-CD$ 16.0% and ${\gamma}-CD$ 13.18% mixture. Based on encapsulation and each optimized combination, the most effective entrapping ${\beta}$-and ${\gamma}-CD$ combination ratio was ${\beta}-CD$ 10% and ${\gamma}-CD$ 13%.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.483-492
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• 2015

This study involved elementary schoolchildren in Busan Metropolitan city and assumed the foundation of social cooperative associations that provide education services for meteorological fields, then we analyzed expected profits in a year for successful operation of first year. Twelve variables relating to profits and expenses were derived, and we used the decision tree for analyzing optimal expected profits. Profit-related variables were lecture's fee per hour and price of textbooks. Expense-related variables were production costs for the textbooks, annual salary for a teacher, education costs for a teacher, developing costs for the textbooks, traveling expenses, rental fees, and operating costs. Besides, by adding education demands, the number of grades, and the number of teachers, we analyzed changes in expected profits, considering variability of profits and expenses. As a result, despite of expected lower demands, to increase price of textbooks and education costs per hour was of advantage to enhance expected profits. The reason is that the more demand, the more increased production costs for textbooks, which is because not to make enough profits to offset the increased expenses due to lowered price of textbooks and education costs. Considering the value of public interest for social cooperative associations, price determination only concerning increase in demands will be avoided.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.4
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• pp.280-293
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• 2005

In this study, a model to calculate the expected total construction cost has been developed by combining a model to calculate the sliding distance of a caisson of a vertical breakwater and a model to calculate the rehabilitation cost of a caisson. The optimal cross-section of a caisson of a vertical breakwater is defined as the cross-section that requires a minimum expected total construction cost within the allowable limit of caisson sliding. Two allowable limits are considered: 0.1 m of the expected sliding distance during the lifetime of the breakwater and 0.1 of the probability that the cumulative sliding distance during the lifetime of the breakwater is greater than 0.3 m. A discount rate has also been introduced to convert the future rehabilitation cost to the present value. The introduction of the discount rate reduces the expected total construction cost for the caissons designed for shorter return periods due to frequent rehabilitations. The present design method requires a smaller cross-section than the conventional deterministic method in shallow water depths, enabling us to design a caisson more economically. On the other hand, the above-mentioned allowable limits of caisson sliding show similar results for smaller water depths, while, for larger depths, the former requires a larger cross-section than the latter.

• Journal of Intelligence and Information Systems
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• v.25 no.2
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• pp.39-55
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• 2019

Recently banks and large financial institutions have introduced lots of Robo-Advisor products. Robo-Advisor is a Robot to produce the optimal asset allocation portfolio for investors by using the financial engineering algorithms without any human intervention. Since the first introduction in Wall Street in 2008, the market size has grown to 60 billion dollars and is expected to expand to 2,000 billion dollars by 2020. Since Robo-Advisor algorithms suggest asset allocation output to investors, mathematical or statistical asset allocation strategies are applied. Mean variance optimization model developed by Markowitz is the typical asset allocation model. The model is a simple but quite intuitive portfolio strategy. For example, assets are allocated in order to minimize the risk on the portfolio while maximizing the expected return on the portfolio using optimization techniques. Despite its theoretical background, both academics and practitioners find that the standard mean variance optimization portfolio is very sensitive to the expected returns calculated by past price data. Corner solutions are often found to be allocated only to a few assets. The Black-Litterman Optimization model overcomes these problems by choosing a neutral Capital Asset Pricing Model equilibrium point. Implied equilibrium returns of each asset are derived from equilibrium market portfolio through reverse optimization. The Black-Litterman model uses a Bayesian approach to combine the subjective views on the price forecast of one or more assets with implied equilibrium returns, resulting a new estimates of risk and expected returns. These new estimates can produce optimal portfolio by the well-known Markowitz mean-variance optimization algorithm. If the investor does not have any views on his asset classes, the Black-Litterman optimization model produce the same portfolio as the market portfolio. What if the subjective views are incorrect? A survey on reports of stocks performance recommended by securities analysts show very poor results. Therefore the incorrect views combined with implied equilibrium returns may produce very poor portfolio output to the Black-Litterman model users. This paper suggests an objective investor views model based on Support Vector Machines(SVM), which have showed good performance results in stock price forecasting. SVM is a discriminative classifier defined by a separating hyper plane. The linear, radial basis and polynomial kernel functions are used to learn the hyper planes. Input variables for the SVM are returns, standard deviations, Stochastics %K and price parity degree for each asset class. SVM output returns expected stock price movements and their probabilities, which are used as input variables in the intelligent views model. The stock price movements are categorized by three phases; down, neutral and up. The expected stock returns make P matrix and their probability results are used in Q matrix. Implied equilibrium returns vector is combined with the intelligent views matrix, resulting the Black-Litterman optimal portfolio. For comparisons, Markowitz mean-variance optimization model and risk parity model are used. The value weighted market portfolio and equal weighted market portfolio are used as benchmark indexes. We collect the 8 KOSPI 200 sector indexes from January 2008 to December 2018 including 132 monthly index values. Training period is from 2008 to 2015 and testing period is from 2016 to 2018. Our suggested intelligent view model combined with implied equilibrium returns produced the optimal Black-Litterman portfolio. The out of sample period portfolio showed better performance compared with the well-known Markowitz mean-variance optimization portfolio, risk parity portfolio and market portfolio. The total return from 3 year-period Black-Litterman portfolio records 6.4%, which is the highest value. The maximum draw down is -20.8%, which is also the lowest value. Sharpe Ratio shows the highest value, 0.17. It measures the return to risk ratio. Overall, our suggested view model shows the possibility of replacing subjective analysts's views with objective view model for practitioners to apply the Robo-Advisor asset allocation algorithms in the real trading fields.

• Journal of Distribution Science
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• v.10 no.10
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• pp.45-57
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• 2012

Purpose - This study was conducted to evaluate service quality, perceived value, and satisfaction in the performing arts in order to establish a system of relationships that predicts repurchase intention, which increasingly needs to be studied as the domestic performing arts market grows. Research design, data, and methodology - Another purpose of this study is to identify 'work-related factors' and 'performing-arts-related factors' in the performing arts industry, and to observe the influence of the core SQ factors expected to influence audiences' purchase intentions through perceived value and customer satisfaction. The empirical study to test the hypothesis was based on a review of the literature and employed the survey method; data were collected from a total of 500 audience members. Results - The major results of the analysis are as follows. First, in terms of quality factors affecting perceived value, literary quality, level, professionalism, and musical quality were shown to have a significant influence as key factors from the performing arts perspective, while reliability, convenience, and related costs were indicated to exert a significant influence as additional factors related to work. Secondly, the quality factors with a significant influence on customer satisfaction were literary quality, professionalism, and musical quality, which were shown to have a significant influence from the performing arts perspective, while only reliability was indicated to exert a significant influence on work-related factors. Third, perceived value was shown to have a strong positive (+) influence on customer satisfaction, with both perceived value and customer satisfaction exerting a significant influence on the revisit intention. Finally, according to the results a difference analysis with demographic variables, viewing variables as moderating variables, differences according to gender were indicated in the influence of literary value and lel on perceived value, and in the influence of convenience and professionalism on customer satisfaction as well. Also, in terms of the influence of perceived value on customer satisfaction, males were found to be more influenced than females. Conclusions - Based on the above results, the suggested implications of the present study are as follows. First, through the consideration of not only the crucial work perspective in performing arts services, which has been inadequate in the past, but the additional performance-related level, the previously unevenly distributed viewpoints were expanded for application. Second, in verifying the relationship between expanded quality factors and the factors that determine consumer behavior while simultaneously considering key factors and additional related factors, work-related service quality factors were shown to exert a stronger influence on perceived value and customer satisfaction than performance-related factors. Third, for service factors related to performance, the reliability factor exerts an influence on perceived value and customer satisfaction, requiring that a performance planner secure and manage diverse channels to immediately support customer requests in providing performance theater services.

• Management & Information Systems Review
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• v.35 no.1
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• pp.143-154
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• 2016

In this research, The new CEO is expected to increase a reporting income through earning management for individual benefit such as a good reputation, high compensation and CEO' s contract extension in the early years of service, of which may influence value relevance of the accounting numbers. We investigate the change of value relevance from 2004 to 2014, compare firms with a change of CEO and firms with non-change of CEO and analysis the value relevance in the early years and in the late years of the new CEO. The results of research are as follows. First, value relevance of EPS of firms with change of CEO are decreased, whereas value relevance of BPS are increased in the regression of all sample. Second, value relevance of EPS are decreased, whereas value relevance of BPS are increased in the early years of the new CEO. This research makes a contribution to provide the first proof about influence of value relevance by the earning management in the early years of the new CEO in Korea.

• Journal of Navigation and Port Research
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• v.45 no.4
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• pp.224-230
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• 2021

It has been 16 years since the government announced its first Ocean Education Policy in 2005. Although the public consensus on the importance of ocean education has been formed, it is impossible to objectively analyze the impact of the policy on the society or the economy. The aim of this paper was to identify differences in perceptions and behaviors about the ocean between groups participating in ocean education and non-participating groups and to analyze the effectiveness of ocean education by developing measurement indicators for the value that individuals gave to ocean education services. To conduct this study, first, the value of ocean education was defined and value items that could be provided to individuals were classified. Second, to develop indicators that could measure classified value items, a Delphi survey was conducted to collect opinions of various experts. Third, by measuring the content validity ratio (CVR) for each item, final indicators and questionnaire were derived. As a result of Delphi analysis, 18 items with a CVR value of 0.6 or higher were finally adopted out of 32 indicator items. In the cognitive value category, indicators that could identify an individual's level of knowledge of the ocean, change in perception, and problem-solving ability were selected. In the behavioral value category, indicators were expanded to judge changes in attitudes and relationships toward the ocean and responsible behavior in more detail. This study is meaningful in that it provides the basis for directly judging the value of ocean education service provided by the government to the people. Results of such analysis are expected to contribute to securing a stable budget and the justification for expanding human resources in the government's continuous promotion of ocean education policies.

• KIEAE Journal
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• v.8 no.5
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• pp.55-60
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• 2008

The purpose of this study is to increase the use of Hwangto and examine the strength according to what it is compounded with. Hwangto-concrete containing Hwanto without cement nor organic chemical products were compared to the traditional cement concrete through some durability experiments. We expect to gain more knowledge on the potentials of Hwangto-concrete as an architectural source. 1) As Hwangto binder amount rises, the value of slump increases too. The reason is that the increase of the quantity of cement causes the increase of the amount of material and the decrease of the amount of aggregate. 2) When the mixed component into Hwangto-concrete remains at 2%, the compress strength is generally dispersed high along the per unit fission, in case the amount of which is at $400(g/m^3)$. The highest compress strength is 39MPa. It means that it can be applied to common structures and we need to conduct a basic property test to ensure the strength and fluidness. 3) Hwangto-concrete is expected to be highly used in the ocean structure and chemical industry because it has better resistance to sulfuric acid and to hydrochloric acid than the cement-concrete has. The result of this study is as follows. It is expected that Hwangto-concrete will be widely applied and further research on its durability and tests for its basic substantial characteristics based on future component added to it.