• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.121-127
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• 2001

The purpose of this paper is to verify and statistically analyze the effect of credit card expenditure on money demand. Statistical analysis was Performed regarding credit spending volume. Ml, M2, M3, non-monetary banking deposit (OFI) and many other parameters based on time-series data for 14 years, from 1985 to 1998. The results suggest that credit card is not the main cause of inflation or increase of money supply but it would become an economic creation on contributing to human life in the coming century. Therefore the monetary authorities must develop the credit card industry, so as to improve positive function of credit cards and to keep controlling some of its negative functions minimally.

• Ocean and Polar Research
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• v.38 no.3
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• pp.225-234
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• 2016

This project sought to conduct an economic feasibility study regarding the commercial production of bio-hydrogen by the marine hyperthermophilic archaeon, Thermococcus onnurineus NA1 using carbon monoxide-containing industrial off-gas. We carried out the economic evaluation of the bio-hydrogen production process using the raw material of steel mill by-product gas. The process parameter was as follows: $H_2$ production rate was 5.6 L/L/h; the conversion of carbon monoxide was 60.7%. This project established an evaluation criterion for about 10,000 tonne/year. Inflation factors were considered as 3%. The operating costs were recalculated based on prices in 2014. The total investment required for development was covered 30% by capital and 70% by a loan. The operation cost for the 0.5-year test and integration, and the cost for the first three months in the 50% production period were considered as the working capital in the cost estimation. The costs required for the rental of office space, facilities, and other related costs from the construction through to full-scale production periods were considered as continuing expenses. Materials, energy, waste disposal and other charges were considered as the operating cost of the development system. Depreciation, tax, maintenance and repair, insurance, labor, interest rate charges, general and administrative costs, lubrication and miscellaneous expenses were also calculated. The hydrogen price was set at US$ 4.15/kg for the economic evaluation. As a result, the process was considered to be economical with the payback period of 6.3 years, NPV of 18 billion Won and IRR of 26.7%.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.83-92
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• 2016

PURPOSES : The purpose of this study was to develop safety performance functions (SPFs) that use zero-inflated negative binomial regression models for urban intersections in central business districts (CBDs), and to compare the statistical significance of developed models against that of regular negative binomial regression models. METHODS : To develop and analyze the SPFs of intersections in CBDs, data acquisition was conducted for dependent and independent variables in areas of study. We analyzed the SPFs using zero-inflated negative binomial regression model as well as regular negative binomial regression model. We then compared the results by analyzing the statistical significance of the models. RESULTS : SPFs were estimated for all accidents and injury accidents at intersections in CBDs in terms of variables such as AADT, Number of Lanes at Major Roads, Median Barriers, Right Turn with an Exclusive Turn Lane, Turning Guideline, and Front Signal. We also estimated the log-likelihood at convergence and the likelihood ratio of SPFs for comparing the zero-inflated model with the regular model. In he SPFs, estimated log-likelihood at convergence and the likelihood ratio of the zero-inflated model were at -836.736, 0.193 and -836.415, 0.195. Also estimated the log-likelihood at convergence and likelihood ratio of the regular model were at -843.547, 0.187 and -842.631, 0.189, respectively. These figures demonstrate that zero-inflated negative binomial regression models can better explain traffic accidents at intersections in CBDs. CONCLUSIONS : SPFs that use a zero-inflated negative binomial regression model demonstrate better statistical significance compared with those that use a regular negative binomial regression model.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.117-125
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• 2014

The temperature distribution of steady state rolling tires with detailed tread blocks is numerically predicted using the three dimensional full patterned tire model. A three dimensional periodic patterned tire model is constructed by copying 1-sector mesh in the circumferential direction. Using the static tire contact analysis, the strain cycles during one revolution are approximated with the strains at Guassian points of the elements which are sector-wise repeated within the same circular ring of elements, by neglecting the tire rolling effect. Based upon the multi-axial fatigue theory, the maximum principal strain is used to represent the combined effect of six strain components on the hysteretic loss. In the following, the deformation due to the inflation and vertical load is calculated using ABAQUS. Then heat generation rate in each element is calculated using an in-house code. Lastly, temperature distribution is calculated using ABAQUS again. Through the numerical experiments, the validity of the proposed prediction method is examined by comparing with the experiment and the temperature distribution of a patterned tire model is compared with those of the main-grooved simple tire model.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.444-460
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• 2017

The duration of volunteering can be analyzed in terms of commitment and attachment. Previous studies have investigated the duration of volunteering predominantly from the perspective of commitment. Alternatively, this study focuses on the concept of attachment and investigates the characteristics of those who volunteer habitually over their whole life, regardless of the regularity and the intensity of the volunteer work. In so doing, the study attempts to identify factors associated with the attachment to volunteering. Data came from a sample of 8,415 participants, ages over twenty who responded to all the surveys of the Korea Welfare Panel Study, from Wave 1 to 10. Zero-inflated negative bionomial regression model was employed to analyze the total number of volunteering in the past ten years. Findings show that people with high attachment to volunteering were those with religion, less education, and a strong sense of reciprocity. Based on the findings, we provide the practical implications for the improved operation and management of volunteer organizations.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.665-673
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• 2014

The Korean film market has revved up against American movies and the movie industry has continued to grow even though Korea is a small country. However, most production staffs who are responsible for practical business of film production get wages that fall short of the inflation rate and minimum wages as temporary employees. And there's the atmosphere that they try to leave film sites on the first opportunity. This study finds that the cause to leave film sites is attributed to perception gaps about the hardworking character and labor which occur in the process that production staffs enter the movie industry and participate in film production as well as poor surroundings. And it should establish staffs' hardworking character and recognition as workers to them by reorganizing the current curriculums which approach movies from the only artistic viewpoint in the departments related to movies and images that hold a large majority in their majors, establishing the concept of work according to participation in film production to potential production staffs, and changing their recognition to improve the elements that they leave the sites.

• Journal of Korean Neurosurgical Society
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• v.57 no.1
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• pp.12-18
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• 2015

Objective : Covered stent has been recently reported as an effective alternative treatment for direct carotid cavernous fistulas (DCCFs). The purpose of this study is to describe our experiences with the treatment of DCCF with covered stents and to evaluate whether a covered stent has a potential to be used as the first choice in selected cases. Methods : From February 2009 through July 2013, 10 patients underwent covered stent placement for a DCCF occlusion. Clinical and angiographic data were retrospectively reviewed. Results : Covered stent placement was performed for five patients primarily as the first choice and in the other five as an alternative option. Access and deployment of a covered stent was successful in all patients (100%) and total occlusion of the fistula was achieved in nine (90%). Complete occlusion immediately after the procedure was obtained in five patients (50%). Endoleak persisted in five patients and the fistulae were found to be completely occluded by one month control angiography in four. The other patient underwent additional coil embolization by a transvenous approach. Balloon inflation-related arterial dissection during the procedure was noted in two cases; healing was noted at follow-up angiography. One patient suffered an asymptomatic internal carotid artery occlusion noted seven months post-treatment. Conclusion : Although endoleak is currently a common roadblock, our experience demonstrates that a covered stent has the potential to be used as the first choice in DCCF; this potential is likely to increase as experience with this device accumulates and the materials continue to improve.

• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.951-961
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• 2011

In this paper, we propose a Bayesian inference using the Markov Chain Monte Carlo(MCMC) method for the zero inflated negative binomial(ZINB) regression model. The proposed model allows the regression model for zero inflation probability as well as the regression model for the mean of the dependent variable. This extends the work of Jang et al. (2010) to the fully defiend ZINB regression model. In addition, we apply the proposed method to a real data example, and compare the efficiency with the zero inflated Poisson model using the DIC. Since the DIC of the ZINB is smaller than that of the ZIP, the ZINB model shows superior performance over the ZIP model in zero inflated count data with overdispersion.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.267-272
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• 2020

Macroeconomics are one of the indicators that are preceded and analyzed when analyzing stocks because it shows the movement of a country's economy as a whole. The overall economic situation at the national level, such as national income, inflation, unemployment, exchange rates, currency, interest rates, and balance of payments, has a great affect on the stock market, and economic indicators are actually correlated with stock prices. It is the main source of data for analysts to watch with interest and to determine buy and sell considering the impact on individual stock prices. Therefore, economic indicators that impact on the stock price are analyzed as leading indicators, and the stock price prediction is predicted through deep learning-based prediction, after that the actual stock price is compared. If you decide to buy or sell stocks by analysis of stock prediction, then stocks can be investments, not gambling. Therefore, this research was conducted to enable automated stock trading by using macro-indicators and deep learning algorithms in artificial intelligence.

• Human Ecology Research
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• v.54 no.2
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• pp.181-195
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• 2016

This study use the influences of parenting style as perceived by and adult child and recognizes gender roles for the purpose of marriage perspectives. I provided a general tendency of parenting style as perceived by and adult child, recognize gender roles, and perspective of marriage to achieve the established goals. We analyzed the relative influence of socio-demographic characteristics, parenting style as perceived by and adult child and recognize gender roles for marriage perspectives. Finally, parenting style as perceived by and adult child are recognized gender roles mediated by the investigated influence of marriage perspectives. We used a structured questionnaire that targeted unmarried men and women 20 to 30 years of age to verify the this study. Data analysis used SPSS ver. 19.0; in addition, we performed reliability, frequency analysis, t-test, hierarchical regression analysis, multiple regression analysis, and variance inflation factor. Looking at these results, both adult children had a higher perception of rearing parents with the usual recognition of gender roles. The analysis indicated a conservative perspective of marriage. Adult children of mothers rearing and recognize gender roles sub-area of masculinity and femininity are perceived to be a significant change observed in marriage perspectives in addition to socio-demographic characteristics of gender and education. However, the relationship between parenting style, as perceived by adult child and marriage perspectives and as analyzed by recognize gender roles, did not have a mediating effect.