• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.633-640
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• 2023

In this study, numerical analysis was performed based on field investigation to derive an appropriate reinforcement method by analyzing the displacement behavior characteristics of concrete blocks generated in the direct fixation track on the bridges of the serviced light rail transit. The track of this study was a direct fixation track on a sharp curved track, and the problem of movement of the concrete blocks installed on the bridge deck in the longitudinal and lateral directions occurred. In this study, based on the finite element model using 3D solid elements, the behavior of the direct fixation track that could be occurred under operating load conditions was analyzed. In addition, the reinforcement effect of various reinforcement methods was analyzed. As a result of analyzing the lateral displacement before and after reinforcement, it was analyzed that the maximum lateral displacement after reinforcement under the extreme lateral wheel loads significantly decreased to about 3% (about 0.1mm) compared to before reinforcement. In addition, as a result of examining the generated stress of the filling mortar, bridge decks, and reinforcing bar, it was analyzed that all of them secured a sufficient safety factor of 2.6 or higher, and the optimal conditions for the reinforcement method were derived. Therefore, it is judged that the number of anchoring reinforcements and symmetrical anchor placement reviewed in this study will be effective in controlling the occurrence of lateral displacement of concrete blocks and securing the structural integrity of bridges and concrete blocks.

• 한국노년학
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• v.30 no.4
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• pp.1179-1195
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• 2010

In this study, we investigated the effects of ego integrity on QoL(Quality of Life) of elderly living alone, where we focused on moderating role of SF36 health factors. To investigate the cause and effect of factors, we purposively collected 282 samples from senior welfare centers in Jeonju city and exploited reliability analysis, confirmatory factor analysis and SEM(Structural Equation Modeling) for 265 cases excluding some cases with missing values. As the results, first, we confirmed ego integrity was positive predictor of QoL. Second, it was proven that the effect of ego integrity on QoL of elderly living alone was stronger in the lower physical functioning group than higher physical functioning group. Third, we also verified that the group with more difficulties in activities or work as a result of poor physical health showed higher effect of ego integrity on QoL. Based on the results, we could explain the reason of conflicts regarding how elderly's health influenced on ego integrity. Also, in the practice of intervention to elderly's problem, we found the health factors could be an indicator of direction or effect of the intervention

• Asia Marketing Journal
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• v.14 no.3
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• pp.49-68
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• 2012

When a channel is vertically separated, there can be inefficiencies, double marginalization. Channel coordination to amend this inefficiency has been an important issue in marketing and economics. Channel coordination deals with maximization of joint profit and achieving proper profit sharing among participants. In this paper, a manufacturer and heterogeneous multiple retailers with exclusive territory are assumed, and channel coordination with two-part tariff is considered. When multiple heterogeneous retailers are assumed, profit sharing can be an issue even though the tariffs based on marginal cost can maximize joint profit. In case of multiple heterogeneous retailers, the manufacturer earns the same profit (fixed fee) from each retailer. This means that a large retailer occupies all the gaps of channel profit between small and large markets. Then, the manufacturer, which generally plays the role of Stackelberg leader, will consider increasing fixed price or marginal price to earn more profit from large retailer. Those reactions can sacrifice maximization of joint profit by making small retailer withdraw or by changing the sales quantities. In this paper, to maximize joint profit and achieve proper profit sharing, two kinds of optional tariffs are considered. The first is an optional two-part tariff based on marginal cost and the second is an optional modified two-part tariff in which marginal prices are higher than the manufacturer's marginal cost. In both types of optional tariffs, maximization of joint profit in each market can be achieved. Moreover, optional tariffs alleviate the problem of profit sharing. Optional tariffs can provide a manufacturer more profit from a large retailer when profit from a small retailer is given. However, the analysis shows that the maximum share of manufacturer from a large retailer is restricted by the condition for self-selection. In case of optional two-part tariffs based on marginal cost, if the gap between demands is large, the maximum share of the manufacturer is sufficient to achieve proper profit sharing. If the gap between demands is not sufficiently large, the manufacturer cannot earn sufficient share from increased profit. An optional modified two-part tariff where marginal price is more than marginal cost of manufacturer is considered because of this scenario. The marginal price above the marginal cost may additionally control the distribution of the increased profit. However, the analysis shows that a manufacturer's maximum profit from a large retailer with given profit from a small retailer is the same as or lower than the maximum profit when optional two-part tariffs based on marginal cost are applied. Therefore, it can be concluded that the optional modified tariffs do not have additional contribution to profit sharing relative to the tariffs based on marginal cost. Although this paper does not cover all kinds of optional tariffs that are different from tariffs based on marginal cost, it shows the advantage of optional tariffs based on marginal cost and has important theoretical implications. The result of this paper also gives guide for channel coordination. Optional two-part tariff based on marginal cost can increase efficiency in channel coordination.

• International Area Studies Review
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• v.15 no.1
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• pp.241-266
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• 2011

This study examines the determinants of proportion of self-employed and their policy implications focusing hotel/restaurant and wholesale/retail sectors in Korea. In this study, we estimate the optimal size of self-employed in Korea using OECD data. Several hypothesis are tested by use of the regression analysis on the panel data of OECD economies during 2000-2007 period. Using the panel data of per capita GNI, unemployment level, income tax burden, we found that the excess supply level of self-employed was about 8.0%~9.5% overall. We also found that the excess supply level of self-employed was 13.7~14.1% for hotel and restaurant sector, and 10.4~11.1% for wholesale and retail sector. This results imply that strategically coordinated programs for noncompetitive sectors are more effectively implemented. Furthermore, more aggressive entry and exit policies are needed to solve the over-supply problem of self-employed in Korea.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.11
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• pp.493-504
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• 2023

The Republic of Korea is located far from the boundary of the earthquake plate, and the intra-plate earthquake occurring in these areas is generally small in size and less frequent than the interplate earthquake. Nevertheless, as a result of investigating and analyzing earthquakes that occurred on the Korean Peninsula between the past two years and 1904 and earthquakes that occurred after observing recent earthquakes on the Korean Peninsula, it was found that of a magnitude of 9. In this paper, the Korean Peninsula Historical Earthquake Record (2 years to 1904) published by the National Meteorological Research Institute is used to analyze the relationship between earthquakes on the Korean Peninsula and statistical self-similarity. In addition, the problem solved through this paper was the first to investigate the relationship between earthquake data occurring on the Korean Peninsula and statistical self-similarity. As a result of measuring the degree of self-similarity of earthquakes on the Korean Peninsula using three quantitative estimation methods, the self-similarity parameter H value (0.5 < H < 1) was found to be above 0.8 on average, indicating a high degree of self-similarity. And through graph visualization, it can be easily figured out in which region earthquakes occur most often, and it is expected that it can be used in the development of a prediction system that can predict damage in the event of an earthquake in the future and minimize damage to property and people, as well as in earthquake data analysis and modeling research. Based on the findings of this study, the self-similar process is expected to help understand the patterns and statistical characteristics of seismic activities, group and classify similar seismic events, and be used for prediction of seismic activities, seismic risk assessments, and seismic engineering.

• The Korean Journal of Applied Statistics
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• v.36 no.5
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• pp.415-445
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• 2023

Oftentimes, the time dependent treatment covariate and the time dependent confounders exist in observation studies. It is an important problem to correctly adjust for the time dependent confounders in the propensity score analysis. Recently, In the survival data, Hade et al. (2020) used a propensity score matching method to correctly estimate the treatment delay effect when the time dependent confounder affects time to the treatment time, where the treatment delay effects is defined to the delay in treatment reception. In this paper, we proposed the Cox model based marginal structural model (Cox-MSM) framework to estimate the treatment delay effect and conducted extensive simulation studies to compare our proposed Cox-MSM with the propensity score matching method proposed by Hade et al. (2020). Our simulation results showed that the Cox-MSM leads to more exact estimate for the treatment delay effect compared with two sequential matching schemes based on propensity scores. Example from study in treatment discontinuation in conjunction with simulated data illustrates the practical advantages of the proposed Cox-MSM.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.365-370
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• 2023

Royalty contributed to the development of the non-fungible token (NFT) ecosystem as a reward system that pays a portion of the sales to the creator whenever transactions occur. This study quantitatively analyzes the impact of the abolition of royalties, which is being expanded by some NFT marketplaces, on the NFT market, and qualitatively analyzes the results of the impact. The analysis results are as follows. First, the number of NFT mints is decreasing by causing creators to leave the NFT market and reducing new entry. Second, major NFT projects have refused to trade with marketplaces that have abolished royalties, leading to a decrease in the number of transactions. Third, the abolition of royalties has undermined the motivation of NFT creators to continue to develop their projects, leading to a drop in NFT floor prices. This study is expected to contribute to reducing the current negative impact in the short term by suggesting how the NFT community provides incentives to owners who voluntarily pay royalties independently of the policy of the NFT marketplace. In addition, it suggests that in the long run, fundamental solutions to the problem of abolishing royalties require improvements in technology related to royalty payments, cooperation between NFT marketplaces and NFT creators, and institutional support related to royalties.

• Journal of Industrial Convergence
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• v.21 no.9
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• pp.11-21
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• 2023

There have been many studies to improve the efficiency of the CG production process, but it was not easy to overcome the problem that it was difficult to check the result in the middle of work and it took a lot of time for rendering. However, as the possibility of using Unreal Live Link, which can check the result in real-time, is increasing, expectations for improving the efficiency of the production process are rising. This study analyzed the efficiency of the 3D animation production process using Unreal Live Link. To this end, modeling, rigging, animation, and layout work were done in Maya, and the final output image sequence was rendered in Unreal Engine through Unreal Live Link. And the difference between this production process and the existing production process in which the final output image sequence is rendered in the 3D software itself was compared and analyzed. As a result of the analysis, unlike the traditional 3D animation production process, it was possible to check the final work result in real-time by proceeding with the work through a high-quality viewport screen, and it was found that the efficiency of work was maximized by deriving the final result through real-time screen capture. Recently, the use of game engines in the 3D animation and film industry is gradually increasing, and the efficiency of work is expected to be maximized if Unreal Live Link is used.

• Journal of The Korean Association For Science Education
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• v.29 no.2
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• pp.203-220
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• 2009

The purpose of this study was to develop a rubric for assessing students' scientific argumentation. Through the analysis of relevant literature related to argument in science education for developing rubric, the procedure in development and the category in assessment for rubric were elicited. According to the general procedure in developing rubric, the standard for evaluating the argumentation derived three categories such as a form, contents, and attitude. The form category was further segmented into sub-functions composition, claim, ground, and conclusion in the whole. The category for contents was segmented into sub-functions understanding, credibility, and inference. And the category for attitude was set to sub-functions participatory level and openness. The standard for evaluating sub-functions in each of the categories formed in this way was minutely suggested with five stages. The rubric, which was developed on the basis of literature, was inspected through a regular seminar in one expert in science education and fellow researchers. The rubric, which was developed in the early days, was again modified by being verified on problem and improvement matter after being entrusted to four experts in scientific education. And, the finally-completed rubric indicated to be high with 0.96 in the content validity index by being verified the validity by the four experts in science education. The developed rubric will lead to being able to increase the understanding about demonstration in students, and to being available for being utilized as the criteria for developing the argumentation process program and for evaluating the argumentation activity.

• Journal of The Korean Association For Science Education
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• v.29 no.8
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• pp.874-885
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• 2009

The purpose of this study is to analyze illustrations, contents, and experiments in 6 kinds of science textbook from the 9th grade covering the phases of the Moon (on the phases of the Moon in six 9th grade science textbook) and to suggest coherent and effective contents and frame of the science textbook. Hence, the researcher decided the study problem. The study problems are as follows; 'Are the illustrations in the science textbook presented to help understand the phases of the Moon depending on the position of the observer?', 'Does the contents of the book clearly mention the phases of the Moon?', 'Can students understand the phases of the Moon through the experiments in the science textbook?', 'Do illustrations, contents, and experiment of the science textbook consistently explain the phases of the Moon?'. 10 persons (9graduate students including the researcher) took part in this study. All things unanimously agreed upon by all participants were reflected in the results. The results are as follows: First, the universal observer's view point is mixed with the earth observer's view in the illustration of these science textbook regarding the phases of the Moon. Moreover, illustrations of some textbooks are presented with such words as 'sunrise', 'midnight' and consequently contain too much. Second, the contents of the science textbook concerning the phases of the Moon is not described clearly. In addition, they don't give clear and detailed explanations for the reason of these changes. Third, all of the textbooks, except one textbook, describe the experiment regarding the phases of the Moon with the earth observer's view point but don't specifically mention that the view point is that of the earth observer's view point. Fourth, illustrations, contents, and experiments in the science textbook don't coherently explain the phases of the Moon. In addition, it is confirmed through the process of the result analysis that the described contents in the science curriculum is not well constructed or logical.