• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.922-929
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• 2022

Purpose: The purpose of this paper is to develop a deep learning model to detect fire extinguishers in images taken from CCTVs in underground utility tunnels. Method: Various fire extinguisher images were collected for detection of fire extinguishers in the running-based underground utility tunnel, and a model applying the One-stage Detector method was developed based on the CNN algorithm. Result: The detection rate of fire extinguishers photographed within 10m through CCTV video in the underground common area is over 96%, showing excellent detection rate. However, it was confirmed that the fire extinguisher object detection rate drops sharply at a distance of 10m or more, in a state where it is difficult to see with the naked eye. Conclusion: This paper develops a model for detecting fire extinguisher objects in underground common areas, and the model shows high performance, and it is judged that it can be used for underground common area digital twin model synchronizing.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.49-55
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• 2022

This study is a secondary data analysis study to confirm the difference in responses to psychological and supportive factors of severely disabled according to proxy responses using the National Survey of the Disabled 2020. 738,169 people with severe disabilities who were 19 years of age or older, whose main disability was not an intellectual disability, were analyzed. χ²-test and t-test were performed using IBM SPSS Statistics 26.0. As a result of the study, the proxy response was more negative in sadness or hopelessness (χ²=952.20, p<.001), suicidal ideation (χ²=369.45, p<.001), and subjective health status (t=30.61, p<.001). And the proxy respondent answered that they need more support from others for daily life (t=209.43, p<.001) and have many difficulties in communication when using medical services (t=41.74, p<.001). When using a proxy response, the researcher should clearly state the point of view that the proxy respondent should take, and interpret the results considering that proxy response may be affected by various factors.

• The Mathematical Education
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• v.62 no.2
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• pp.269-287
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• 2023

Matrix theory is widely used not only in mathematics, natural sciences, and engineering, but also in social sciences and artificial intelligence. In the 2009 revised mathematics curriculum, matrices were removed from high school math education to reduce the burden on students, but in anticipation of the age of artificial intelligence, they will be reintegrated into the 2022 revised education curriculum. Therefore, there is a need to analyze the matrix content covered in other countries to suggest a meaningful direction for matrix education and to derive implications for textbook composition. In this study, we analyzed the German mathematics curriculum and standard education curriculum, as well as the matrix units in the German Hesse state mathematics curriculum and textbook, and identified the characteristics of their content elements and development methods. As a result of our analysis, it was found that the German textbooks cover matrices in three categories: matrices for solving linear equations, matrices for explaining linear transformations, and matrices for explaining transition processes. It was also found that the emphasis was on mathematical reasoning and modeling when learning matrices. Based on these findings, we suggest that if matrices are to be reintegrated into school mathematics, the curriculum should focus on deep conceptual understanding, mathematical reasoning, and mathematical modeling in textbook composition.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.4
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• pp.213-220
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• 2023

This paper presents a model simulating the folding process and collision dynamics of "ddakji", a traditional Korean game played using paper tiles (which are also referred to as ddakji). The model uses two A4 sheets as the base materials for ddakji. The folding process involves a series of boundary conditions that transform the wing part of the paper structure into a twisted configuration. A rigid plate boundary condition is also adopted for squeezing, establishing the shape and stress state of the game-ready ddakji through dynamic relaxation analysis. The gaming process analysis involves a forced displacement of the striking ddakji to a predetermined collision position. Collision analysis then follows at a given speed, with the objective of overturning the struck ddakji--a winning condition. A genetic algorithm-based optimization analysis identifies the optimal collision conditions that result in the overturning of the struck ddakji. For efficiency, the collision analysis is divided into two stages, with the second stage carried out only if the first stage predicts a possible overturn. The fitness function for the genetic algorithm during the first stage is the direction cosine of the struck ddakji, whereas in the second stage, it is the inverse of the speed, thus targeting the lowest overall collision speed. Consequently, this analysis provides optimal collision conditions for various compression thicknesses.

• Journal of Technology Innovation
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• v.31 no.2
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• pp.333-369
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• 2023

In this paper, the effect of government corporate support projects on corporate growth was analyzed, and the effect on corporate financial performance or non-financial performance was empirically analyzed by using the growth stage as a modulating variable in government support activities. As a result, it was analyzed that government corporate support had a significant effect on financial performance, non-financial performance, and use of government support, and that the moderating effect of the growth stage had a positive (+) effect on both financial and non-financial performance. Taken together, the research results showed that government corporate support had a positive effect on corporate performance, the growth stage had a positive (+) effect on both financial and non-financial performance, and the impact on financial performance was even greater. Accordingly, government support projects must be supported according to each company's growth stage, and during the decline, companies need to provide customized support according to the state of the company through industry and corporate analysis, and it is expected to be meaningful to improve the efficiency of the government's business support project.

• Therapeutic Science for Rehabilitation
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• v.12 no.3
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• pp.61-77
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• 2023

Objective : This study analyzed the correlation between cognitive function and oral health-related quality of life (OHQoL). Methods : Demographic and clinical characteristics were extracted and utilized for subjects aged 45 years or older who participated in the 8th Korean Longitudinal Study on Aging in 2020. The dependent variable was the Geriatric Oral Health Assessment Index, and the independent variable was the level of cognitive function classified by the Mini-Mental State Examination scores. The analysis method used inverse probability of treatment weighting (IPTW). Then, the association between cognitive function and OHQoL was analyzed by multiple regression analysis. Results : Among the participants, 4,367 (71.40%) had normal cognition, 1,155 (18.89%) had moderate cognitive impairment, and 594 (9.71%) had severe cognitive impairment. As a result of analysis by applying IPTW, there was a negative correlation between the cognitive function group and OHQoL (normal vs. moderate: β = -2.534, p < .0001; normal vs. severe: β = -2.452, p < .0001). Conclusion : After propensity score matching, mild cognitive impairment showed a more negative association than severe cognitive impairment. Therefore, patients with cognitive impairment require oral health management education to improve OHQoL regardless of the level of cognitive impairment.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.139-149
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• 2010

Internet was designed for network scalability and best-effort service which makes all hosts connected to Internet to be vulnerable against attack. Many papers have been proposed about attack detection algorithms against the attack using IP spoofing and DoS/DDoS attack. Purpose of DoS/DDoS attack is achieved in short period after the attack begins. Therefore, DoS/DDoS attack should be detected as soon as possible. Attack detection algorithms using false alarm rates consist of the false negative rate and the false positive rate. Moreover, they are important metrics to evaluate the attack detections. In this paper, we analyze the performance of the attack detection algorithms using the impact of false negative rate and false positive rate variation to the normal traffic and the attack traffic by simulations. As the result of this, we find that the number of passed attack packets is in the proportion to the false negative rate and the number of passed normal packets is in the inverse proportion to the false positive rate. We also analyze the limits of attack detection due to the relation between the false negative rate and the false positive rate. Finally, we propose a solution to minimize the limits of attack detection algorithms by defining the network state using the ratio between the number of packets classified as attack packets and the number of packets classified as normal packets. We find the performance of attack detection algorithm is improved by passing the packets classified as attacks.

• Iberoamérica
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• v.21 no.2
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• pp.83-114
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• 2019

Now Venezuela is the most attentional country in Latin America not only in our country but also all world. Unfortunately, the current crisis is a danger that threatening the venezuelan people's right to live, so most of the news is negative. Some analysts in Korea insist that everything is the result of invasion by US imperialism, others say it is a state of default due to excessive populism. The others also described as a power game of the powers of the world by the new Cold War. But most essential thing is that Sovereign of Venezuela, Venezuelan people are marginalized in this process. Venezuela's crisis seems to have been both a combination of internal and external factors, but internal factors been a main cause. The internal factors are the dictatorship and corruption of crony capitalism of nepotism which are considered historical ailments in Latin America. Chávez criticized the oligarchy, but paradoxically, the Chávezian or current ruling forces became another oligarchy. Unfortunately, Western powers such as the United States and the EU and Venezuela's current ruling powers are at an extreme confrontation, so can be seen using cliff-edge tactics. The best solution is the free and peaceful reelection of the president. After the patriarchal winter, which spring will come the Venezuelan people must decide.

• Journal of International Area Studies (JIAS)
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• v.12 no.4
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• pp.67-88
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• 2009

In April, 1995, ANC government was established in South Africa. The Black government set up Truth and Reconciliation Committee in November, 1995. The Committee investigated approximately 50,000 cases for 3years. Through this process, Black and White in SA could be united into one. Finally, the system of racial discrimination, lasting for about 300 years, was abolished. The Committee played a role as a social infra-structure, which was to perform and solidify democracy in SA. Reconciliation, agreement, Participation, equality, Communication, and Reformation of law system were practically implemented by the Committee. Many people evaluate TRC's activity, which had the reformative and democratic character of the object of investigation, investigative criterion, investigative process, and the approval of investigative result. But De Klerk evaluates that TRC retaliated the White with legal. J. Cronin evaluates that TRC transiently change democracy of the South Africa, and many other social movement groups had a negative view about TRC. But the Black and White in South Africa transformed 'discriminated society' into 'united one'. The Committee took the initiative in such a change. The Committee was not an organization needed for the policy, but the committee was the policy itself to change the former society to the new one. Now The ANC government was forwarding TRC's roles and functions to the truth and reconciliation bureau of the Justice Department for further action. The ANC government has to execute some policy for social reconciliation. Firstly, the government needs to build construction social and national system for making close investigation into the White's historical guilt. Secondly, it must be executed to TRC's recommendation pursuit social reform of social infra-structure in the South Africa. Thirdly, The government should execute policy for the Black's right as labors and social member. Lastly, the government must investigate still-remaining historic state violence and infringement of human right for social reconciliation.

• Journal of The Geomorphological Association of Korea
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• v.17 no.2
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• pp.63-76
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• 2010

The Jangdo wetland is located on a very gentle slope of the mountain area in Daejangdo island, Shinan-gun, Korea, in which the area of the watershed is estimated at 147,000 m². The wetland has been regarded as a peat bog without any sedimentological evidence. This study was conducted to analyze the geomorphological and sedimentological characteristics of the wetland. The geographic information system (GIS) was used to analyze the drainage system, and field surveys were conducted to measure the range and depth of wetland deposits. The grain size analysis, organic matter determination, elements analysis and radiocarbon dating were performed on samples from the wetland. As a result, the wetland deposits were about 30 cm deep on average, the mean grain sizes ranged from 50 to 500 μm, and the average C/N ratio was 11.5. The portion of organic matter it contained was only 5~26%, which did not satisfy the peat standards. The radiocarbon ages from the wetland deposits range 180±50 ¹⁴C yr BP to modern, which indicated that natural and anthropogenic interferences including agricultural activities have continuously happened. We conclude that the Jangdo wetland is still in its infancy, not a steady state, so that it could be very sensitive to a small disturbance.