• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.3
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• pp.119-131
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• 2009

The world's widely used key exchange protocols are open cryptographic communication protocols, such as TLS/SSL, whereas in the financial field in Korea, key exchange protocols developed by industrial classification group have been used that are based on PKI(Public Key Infrastructure) which is suitable for the financial environments of Korea. However, the key exchange protocols are not only vulnerable to client impersonation attacks and known-key attacks, but also do not provide forward secrecy. Especially, an attacker with the private keys of the financial security server can easily get an old session-key that can decrypt the encrypted messages between the clients and the server. The exposure of the server's private keys by internal management problems, etc, results in a huge problem, such as exposure of a lot of private information and financial information of clients. In this paper, we analyze the weaknesses of the cryptographic communication protocols in use in Korea. We then propose two key exchange protocols which reduce the replacement cost of protocols and are also secure against client impersonation attacks and session-key and private key reveal attacks. The forward secrecy of the second protocol is reduced to the HDH(Hash Diffie-Hellman) problem.

• Journal of Korea Water Resources Association
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• v.54 no.spc1
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• pp.1183-1193
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• 2021

Low flow affects various fields such as river water supply management and planning, and irrigation water. A sufficient period of flow data is required to calculate the Flow Duration Curve. However, in order to calculate the Flow Duration Curve, it is essential to secure flow data for more than 30 years. However, in the case of rivers below the national river unit, there is no long-term flow data or there are observed data missing for a certain period in the middle, so there is a limit to calculating the Flow Duration Curve for each river. In the past, statistical-based methods such as Multiple Regression Analysis and ARIMA models were used to predict sulfur in the unmeasured watershed, but recently, the demand for machine learning and deep learning models is increasing. Therefore, in this study, we present the DNN technique, which is a machine learning technique that fits the latest paradigm. The DNN technique is a method that compensates for the shortcomings of the ANN technique, such as difficult to find optimal parameter values in the learning process and slow learning time. Therefore, in this study, the Flow Duration Curve applicable to the unmeasured watershed is calculated using the DNN model. First, the factors affecting the Flow Duration Curve were collected and statistically significant variables were selected through multicollinearity analysis between the factors, and input data were built into the machine learning model. The effectiveness of machine learning techniques was reviewed through statistical verification.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.95-108
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• 2022

The increase in the use time of tunnel users due to the lengthening of the road tunnel may increase the evacuation time in case of fire, resulting in a large number of casualties. In order to reduce the casualties caused by fire, the "Road Tunnel Design Manual, Part 6 Tunnel" and "Road Tunnel Disaster Prevention Facility Installation and Management Guidelines" stipulate that ventilation facilities should be installed along with the extension of the tunnel. The ventilation system design factor considers the wind speed of the external natural wind to be at least 2.5 m/s, and it is applied upward according to the characteristics of the tunnel. As a result of analyzing the five-minute average wind speed data in the Daegwallyeong region for the past 6 years, it was analyzed that 15.8% of the windy days were winds of 10 m/s or more, and the maximum was 20 m/s. Therefore, in this study, when a fire occurs in a tunnel, the pattern of natural wind flowing into the tunnel and the backlayering distance of the tunnel fire smoke according to the maximum wind speed were analyzed. As a result, it was analyzed that a backflow of up to 490 m occurs when a gust of 20 m/s blows.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.248-256
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• 2021

After the COVID-19 pandemic, hand hygiene has become more important to prevent and reduce infection. To manage and provide water to ensure safe handwashing, water governance and the role of public servants are also getting critical. Many organizations have given their priority to capacity building of public servants. In the Strategic Plan for the ninth phase of the Intergovernmental Hydrological Programme (2022-2029), 'Water education in the Fourth Industrial Revolution' is included as a priority. In Korea, ODA in the field of water and sanitation is emphasized in Korea's 3rd Mid-term Strategy for Development Cooperation (2021-2025). Also, KOICA and various water-related organizations have been organizing water education programs for developing countries. This study presents the direction for water education for public servants in developing countries in the post COVID-19 through the education program cases of the International Centre for Water Security and Sustainable Management established by the agreement between the Korean government and UNESCO in 2017. The study suggests that water-related organizations should cooperate with each other to prevent duplication of water education contents. It also suggests that blended learning should be actively utilized for the improvement of education program effectiveness. Lastly, the study emphasizes that education demand for the water technologies related to the fourth industrial revolution and smart water management is increasing, which should be considered when water-related organizations create online content or design education programs.

• Journal of Korean Library and Information Science Society
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• v.53 no.3
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• pp.377-404
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• 2022

This study analyzes trends in research topics and related terms in the field of library science in North Korea. To this end, subject fields in library and information science (LIS) in South Korea, which corresponds to that of the North, were divided into seven subject categories and 25 detailed subject areas. In addition, 136 research articles published in two North Korean journals were reclassified and analyzed according to South Korea's detailed subject areas. The detailed topic area in the field of LIS is based on the criteria for posting papers of three major academic journals in the field of LIS in South Korea. The two academic journals in North Korea that were the subject of this study were "Kim Il-Seong University Journal (Language Literature)" (2008-2018) and "Reference Materials for Librarians" (2016-2017). This study not only informs South Korean researchers the trends of interest in North Korea's recent library and library science, but can also be the starting point for academic exchanges between researchers in South and North Korean libraries and related fields in the future.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.23-34
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• 2009

In the railroad rolling stock depot, long-term maintenance tasks is done regularly every two or four year basis to maintain the functionality of equipments and rolling stock body or for the repair operation of the heavily damaged rolling stocks by fatal accidents. This paper addresses the computer simulation model building for the rolling stock maintenance shop for the CDC(Commuter Diesel Car) and Generator Car planned to be constructed at Daejon Rolling Stock Depot, which will be moved from Yongsan Rolling Stock Depot. We evaluated the processing capacity of two layout design alternatives based on the maintenance process chart through the developed simulation models. The performance measures are the number of processed cars per year, the cycle time, shop utilization, work in process and the average number waiting car for input. The simulation result shows that one design alternative outperforms another design alternative in every aspect and superior design alternative can process total 340 number of trains per year 15% more than the proposed target within the current average cycle time.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.231-238
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• 2023

The position of a light buoy is always flexible due to the influence of external forces such as tides and wind. The position can be checked through AIS (Automatic Identification System) or RTU (Remote Terminal Unit) for AtoN. As a result of analyzing the position data for the last five years (2017-2021) of a light buoy, the average position error was 15.4%. It is necessary to detect position error data and obtain refined position data to prevent navigation safety accidents and management. This study aimed to detect position error data and obtain refined position data by DBSCAN Clustering position data obtained through AIS or RTU for AtoN. For this purpose, 21 position data of Gunsan Port No. 1 light buoy where RTU was installed among western waters with the most position errors were DBSCAN clustered using Python library. The minPts required for DBSCAN Clustering applied the value commonly used for two-dimensional data. Epsilon was calculated and its value was applied using the k-NN (nearest neighbor) algorithm. As a result of DBSCAN Clustering, position error data that did not satisfy minPts and epsilon were detected and refined position data were acquired. This study can be used as asic data for obtaining reliable position data of a light buoy installed with AIS or RTU for AtoN. It is expected to be of great help in preventing navigation safety accidents.

• Korean Journal of Culture and Social Issue
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• v.9 no.spc
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• pp.35-55
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• 2003

The purpose of this study is to review the previous studies on the safety problems in Korea and to propose a psychological total safety system model. The model consisted of four agents; the government as the safety management agent, the suppliers of safety goods and services, consumer of safety goods and services, and civil movement institutions for safety. It was emphasized that the culture specific social representations of safety and accident have emerged in the course of rapid industrialization process in Korea during last 30 years. We delineated the social representations of the Korean people on safety and accident according to the model. A psychological analysis of drinking and driving behavior was performed as an application of the model. It was emphasized that safety psychologists have to develope and to apply the knowledge and the information from human engineering psychology and applied social psychology on safety and accidents.

• Journal of Korean Dental Hygiene Science
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• v.6 no.2
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• pp.1-12
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• 2023

Objectives: This study attempted to identify the eating habits and oral health behaviors of Korean teenagers, studying their relationship with oral health status. The findings serve as fundamental data to enhance proper eating habits and oral health-related projects, ultimately improving teenagers' oral health. Methods: It was analyzed through the original data of the 16th (2020) online survey of youth health behavior in Korea, Frequency analysis, complex sample cross-analysis, complex sample logistic regression analysis were conducted using the SPSSwin 21.0 program. Results: As a result of the study, was associated with the consumption of all sweet drinks, fast food intake, and the frequency of daily brushing over the past 7 days Teeth pain is noted with the consumption of soda, sweet drinks, fast food, and the frequency of daily brushing over the past 7 days. Gum bleeding is noted with the consumption of sweetened products, fast food intake, and the frequency of daily brushing over the past 7 days. Conclusions: Eating habits and oral health behaviors should be considered for the oral health management of middle and high school students. Specific measures should be sought to provide proper dietary education and systematic oral health education to improve the oral health of middle and high school students.

• The Korean Society of Law and Medicine
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• v.21 no.2
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• pp.105-162
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• 2020

In the pandemic of infectious disease, restrictions of individual liberty have been justified in the name of public health and public interest. In March 2020, the National Assembly of the Republic of Korea passed the revised bill of the 「Infectious Disease Control and Prevention Act.」 The revised bill newly established the legal basis for forced testing and disclosure of the information of confirmed cases, and also raised the penalties for violation of self-isolation and treatment refusal. This paper examines whether and how these individual liberty limiting clauses be justified, and if so on what ethical and philosophical grounds. The authors propose the theories of the philosophy of law related to the justifiability of liberty-limiting measures by the state and conceptualized the dual-aspect of applying the liberty-limiting principle to the infected patient. In COVID-19 pandemic crisis, the infected person became the 'Patient as Victim and Vector (PVV)' that posits itself on the overlapping area of 'harm to self' and 'harm to others.' In order to apply the liberty-limiting principle proposed by Joel Feinberg to a pandemic with uncertainties, it is necessary to extend the harm principle from 'harm' to 'risk'. Under the crisis with many uncertainties like COVID-19 pandemic, this shift from 'harm' to 'risk' justifies the state's preemptive limitation on individual liberty based on the precautionary principle. This, at the same time, raises concerns of overcriminalization, i.e., too much limitation of individual liberty without sufficient grounds. In this article, we aim to propose principles regarding how to balance between the precautionary principle for preemptive restrictions of liberty and the concerns of overcriminalization. Public health crisis such as the COVID-19 pandemic requires a population approach where the 'population' rather than an 'individual' works as a unit of analysis. We propose the second expansion of the harm principle to be applied to 'population' in order to deal with the public interest and public health. The new concept 'risk to population,' derived from the two arguments stated above, should be introduced to explain the public health crisis like COVID-19 pandemic. We theorize 'the extended harm principle' to include the 'risk to population' as a third liberty-limiting principle following 'harm to others' and 'harm to self.' Lastly, we examine whether the restriction of liberty of the revised 「Infectious Disease Control and Prevention Act」 can be justified under the extended harm principle. First, we conclude that forced isolation of the infected patient could be justified in a pandemic situation by satisfying the 'risk to the population.' Secondly, the forced examination of COVID-19 does not violate the extended harm principle either, based on the high infectivity of asymptomatic infected people to others. Thirdly, however, the provision of forced treatment can not be justified, not only under the traditional harm principle but also under the extended harm principle. Therefore it is necessary to include additional clauses in the provision in order to justify the punishment of treatment refusal even in a pandemic.