• Journal of radiological science and technology
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• v.36 no.2
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• pp.111-122
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• 2013

This study was carried out to reduce patient dose through focus-detector distance, kilovoltage, and a combination of copper filters. In the C, L-spine lateral, Skull AP views were obtained by making changes of 60-100 kV in tube voltage and of 100-200 cm in focus-detector distance and by adding a copper filter when using an auto exposure control device in the digital radiography equipment. The incident dose showed 90 kV, 0.3 mmCu in C-spine lateral with 0.06 mGy under the condition of 200 cm; 100 kV, 0.3 mmCu with 0.40 mGy under the condition of 200 cm and 90 kV 0.3 mmCu in Skull AP with the lowest value of 0.24 mGy under the condition of 140 cm. It was observed that entrance surface dose decreased the most when was increased by 150 cm, 70 kV (C-spine lateral), 81 kV (L-spine lateral). It was also found out that as the between the focus-detector increased in the expansion of the video decreased but the difference was not significant when the distance was 180 cm or more. Skull AP showed the most reduction in the entrance surface dose when the tube voltage was changed by 80 kV, 0.1 mmCu, and 120 cm. Therefore, when using the automatic exposure control device, it is recommended to use the highest tube voltage if possible and to increase focus-detector distance at least by 150~200 cm in wall and 120~140 cm in table in consideration of the radiotechnologist's physical conditions, and to combine 0.1~0.3 mmCu and higher filters. It is thus expected to reduce patient dose by avoiding distortion of images and reducing the entrance surface dose.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.533-542
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• 2017

In diagnostic radiology, the imaging system has been changed from film/screen to digital system. However, the method for removing scatter radiation such as anti-scatter grid has not kept pace with this change. Therefore, authors have devised the indirect flat panel detector (FPD) system with net-like lead in substrate layer which can remove the scattered radiation. In clinical context, there are many radiographic examinations with angulated incident X-ray. However, our proposed FPD has net-like lead foil so the vertical lead foil to the angulate incident X-ray would have bad effect on its performance. In this study, we identified the effect of vertical/horizontal lead foil component on the novel system's performance and improved the structure of novel system for clinical usage with angulated incident X-ray. Grid exposure factor and image contrast were calculated to investigate various structure of novel system using Monte Carlo simulation software when the incident X-ray was tilted ($0^{\circ}$, $15^{\circ}$, and $30^{\circ}$ from the detector plane). More photons were needed to obtain same image quality in the novel system with vertical lead foil only then the system with horizontal lead foil only. An optimal structure of novel system having different heights of its vertical and horizontal lead foil component showed improved performance compared with the novel system in a previous study. Therefore, the novel system will be useful in a clinical context with the angulated incident X-ray if the height and direction of lead foil in the substrate layer are optimized as the condition of conventional radiography.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.21-28
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• 2021

The purpose of this study is to analyze the efficiency of the policy direction to see if the government's purpose of relocating public institutions was achieved by analyzing the case of the Korea Housing Finance Corporation, which moved to Busan Metropolitan City in 2014. Based on the Korea Housing Finance Corporation's settlement management disclosure and public institution performance evaluation report from 2009 to 2019, efficiency was compared and analyzed using DEA analysis, work efficiency in management performance evaluation report, and financial ratio. The analysis results are as follows. First, in the case of DEA analysis, the difference in efficiency before and after fat transfer was not noticeable. Second, the efficiency analysis using the performance evaluation report and the financial ratio showed that the efficiency decreased after local relocation. Taken together, in the case of the Korea Housing Finance Corporation, efficiency decreased after local relocation, which can be attributed to sluggish business performance and inefficiency related to financial ratios. However, this study has limitations because it conducted an analysis on the Korea Housing Finance Corporation. To compensate for this, it is necessary to diversify the scope of research targeting all fund-managed quasi-governmental institutions in Korea. Nevertheless, this study is the first study to analyze before and after the relocation of fund-managed quasi-governmental institutions, and is expected to provide significant implications for future policies to be discussed.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.549-555
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• 2021

This study reviewed the important preceding studies of prevention and treatment of the crimes and therapies on the characteristics of mental illness, trying to investigate and identify more effective ways to prevent, decrease the crimes of the mentally ill and treat them. The main results were as follows. First, relationships between mental illness and crimes have been inconsistently reported, to investigate environmental stresses and triggers of the mentally ill additionally. Second, the term 'mentally illness' was to be defined more specifically, such as severe psychiatric disabled, antisocial personality disorder, intellectual disability, anger·impulse control disorder, and drug abuse. If medication and psychosocial treatments were properly treated to the severe psychiatric disabled, their crime incidence and recidivism will be decrease enough to live with their neighbors in community. But the ways and processes of treating antisocial personality disorder, intellectual disability, anger·impulse control disorder, and drug abuse were very different from it, requiring more intense psychological, medical and biological interventions and social seclusion. The national campaigns and projects for their human rights and community care will be needed to promote the therapeutic effects for them. The limitation and future tasks were discussed.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.275-285
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• 2021

The purpose of this study is to empirically identify the process of technology acceptance of the metaverse, a virtual world-based platform that has attracted attention due to the 4th industrial revolution and the COVID-19 pandemic. The technology acceptance model (TAM) was used to identify factors affecting the use of the metaverse platforms and to analyze the causal relationship among these factors. For research, a survey was conducted on ordinary adult men and women and was analyzed using a structural equation model. The study found that perceived pleasure, interactivity, self-efficacy, and social influence had a positive effect on perceived ease-of-use. Interactivity and social influence had a statistically significant effect on perceived usefulness. The relationship between perceived ease-of-use and perceived usefulness was not statistically significant, but both perceived ease-of-use and perceived usefulness had a significant effect on positively forming attitudes toward metaverse. Lastly, favorable attitudes toward the metaverse platform had a positive effect on the intention to continue using it. Through this study, it was possible to identify the factors affecting the intention to use the metaverse and to confirm the causal relationship between the factors. A deeper understanding of users may be obtained in future if the research subject can be expanded and investigated with various factors.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.141-149
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• 2021

This study investigated the effect of accounting information on dividend policy as a measure of corporate conservatism from the perspective of the internal accounting management system. The verification is based on a sample of 543 companies listed on securities (excluding KOSDAQ and financial industry) among the Bank of Korea (2019) 「2018 Corporate Management Analysis」 and company analysis of the Korea Productivity Center (financial data disclosed as listed companies as a December settlement company) was composed. Using SPSS 22, empirical analysis was conducted using exploratory factor analysis and regression analysis. The first is the verification related to corporate conservatism and the role of dividend policy, and it is verification of whether internal accounting management influences financial decision-making. Second, if internal accounting management exists, it is a verification of how conservatism and investment policies (in-house reserve, debt borrowing, capital increase, dividends, etc.) affect the corporate value according to accounting information. As a result, from the perspective of the internal accounting management system, it was found that among the variables of accounting information, profitability can have a positive effect on corporate conservatism and dividend policy as a corporate valuation method of reinvestment. In addition, it has been proven that corporate conservatism has an effect on profitability-to-value through capital accumulation and reinvestment such as surplus and internal reserves. In the future, we will study and discuss the complementarity of corporate conservatism and dividend policy in relation to governance structure and improvement of the internal accounting management system.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.263-268
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• 2021

The purpose of this study was to propose a model which is suitable for the actual delivery system by designing a fetal delivery hospital operation management and fetal health classification model. The number of deaths during childbirth is similar to the number of maternal mortality rate of 295,000 as of 2017. Among those numbers, 94% of deaths are preventable in most cases. Therefore, in this paper, we proposed a model that predicts the health condition of the fetus using data like heart rate of fetuses, fetal movements, uterine contractions, etc. that are extracted from the Cardiotocograms(CTG) test using a random forest. If the redundancy of the data is unbalanced, This proposed model guarantees a stable management of the fetal delivery health management system. To secure the accuracy of the fetal delivery health management system, we remove the outlier which embedded in the system, by setting thresholds for the upper and lower standard deviations. In addition, as the proportion of the sequence class uses the health status of fetus, a small number of classes were replicated by data-resampling to balance the classes. We had the 4~5% improvement and as the result we reached the accuracy of 97.75%. It is expected that the developed model will contribute to prevent death and effective fetal health management, also disease prevention by predicting and managing the fetus'deaths and diseases accurately in advance.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.417-426
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• 2019

This researched is an investigation about the youths runaways street life experienced, the crimes committed through the influenced living in the street by looking into the effectiveness of the youth welfare and make an observation of their direction. The survey was conducted on young people who met in the youth shelter and outreach program, and finally analyzed 259 copies. The results of the study are as follows. First, When comparing the ages of the runaway youths if not properly given a support, services and prevention after running away from home, these youth will live their life in the street until their adolescents. Second, Runaway youth shelter has been providing the needs of those runaway youth who came in the shelter. However, it needs necessary new policy and services that will augment the support in solving problems of the youths when they visit youth shelter to ask for help and support. Third, It can be seen that the flight behavior after the street life is increased. They are in a situation where they have no choice but to join the juveniles for street life. Finally, Street life Youth self-reliance, support for living expenses, housing facilities, job opportunities, technical and job skill training were highly desired by the youths. Eventually, the intervention of youth living in street life requires a multifaceted support such as housing, labor, education, and welfare.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.257-266
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• 2018

The implication of this study is that the development and market participation of the next generation eco - friendly vehicles is accelerating, and consumers 'interest is increasing. Also, the product attributes of environment - friendly vehicles and the government's policy support for the next generation eco - friendly vehicles. The purpose of this study is to investigate the effect of purchasing behavior of eco-friendly vehicles on the product attributes of eco-friendly vehicles. Economic, image, functionality, and service convenience have positive effects on consumers' purchase intention. As a result of examining the moderating effect of the government support policy between the product attributes of environment - friendly vehicles and the purchase intentions of environment - friendly vehicles, the government or municipal government has no control effect such as vehicle price subsidy, vehicle tax subsidy, Carbon tax support to prevent emissions was found to have a moderating effect of supporting 10,000 won per ton, even if 5,000 won per ton was supported. This suggests that consumers who prefer to buy eco-friendly vehicles are more likely to have environmental factors.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.1-10
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• 2018

For local festivals to be successful, it is important to cooperate with various entities and effectively utilize festival-related resources. Recently, many efforts have been made to improve the operation and management performance of local festivals in Korea, but systematic management and IT support have been insufficient. In this study, the factors affecting the IT governance of local festivals were derived through a literature review and the relationship to the festival performance was analyzed empirically. A survey was conducted with local festival organizers and stake holders, and the research model was verified using the regression analysis with total 109 samples. According to the results of the analysis, it was confirmed that marketing, processes and service management have a significant effect on festival performance within IT governance. The effect of festival performance on resource management was not statistically significant. This study demonstrates that the systematic operation and management of local festivals using IT governance is necessary for local festivals. It will be more meaningful if further study discuss the IT utilization guidelines and success cases through the innovative use of IT for local festivals.