• Journal of Radiation Protection and Research
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• v.46 no.3
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• pp.106-111
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• 2021

Background: Crookes tube is utilized in junior high and high schools in Japan to study the character of electrons and current, and not for radiological education. There is no official guideline or regulation for these radiation source to the public. Therefore, most teachers have no information about the leakage of X-rays from Crookes tube. The peak energy of X-rays is approximately 20 keV, and it is impossible to measure using conventional survey meters. Materials and Methods: Each leakage dose of low energy X-rays from 38 Crookes tube in the education field, such as junior and senior high schools in Japan, was explored by the teachers in the school using radio-photoluminescence (RPL) dosimeters. Before and after the measurements, the dosimeters were sent by postal mails. Results and Discussion: At the exploration in this study, it was estimated that the 70 ㎛ dose equivalent, H_p(0.07) of X-rays from 31 Crookes tubes were smaller than 100 µSv in 10 minutes, at the distance of 1 m, where the Crookes tube was usually observed. However, the highest dose was estimated as 0.69 mSv by an equipment with the full power. Furthermore, one Crookes tube exhibited 0.62 mSv with minimum output power of the induction coil. This relatively large dose was reduced by the shorter distance of discharge electrodes of the induction coil. Conclusion: The leakage dose of low energy X-rays from 38 Crookes tube was explored using RPL dosimeters. It was estimated that the H_p(0.07) of X-rays from 31 Crookes tubes were smaller than 100 µSv in 10 minutes at the distance of 1 m, while some equipment radiated a higher dose. With this study, the provisional guideline for the safety operation of Crookes tube is established.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.175-181
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• 2021

Objectives: The correlation between the size of a leak hole, the volume of the leakage, and the range of influence was investigated for a hydrochloric acid tank-lorry. Methods: For the case of a tank-lorry chemical accident, KORA (Korea Off-site Risk Assessment Supporting Tool) was used to predict the leak rate and the range of influence according to the size of the leak hole. The correlation was studied using R. Results: As a result of analyzing the leak rate change according to the leak hole size in a 35% hydrochloric acid tank-lorry, as the size of the leak hole increased from 1 to 100 mm, the leak rate increased from 0.008 to 83.94 kg/sec, following the power function. As a result of calculating the range of influence under conditions ranging from 1 to 100 mm in size and 10 to 60 minutes of leakage time, it was found that the range spanned from a minimum of 5.4 m to a maximum of 307.9 m. As a result of multiple regression analysis using R, the quadratic function model best explained the correlation between the size of the leak hole, the leak time, and the range of influence with an adjected coefficient of determination of 0.97 and a root mean square error of 22.33. Conclusion: If a correlation database for the size of a leak hole is accumulated for various substances and under various conditions, the amount of leakage and the range of influence can easily be calculated, facilitating field response activities.

• Journal of Digital Convergence
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• v.19 no.7
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• pp.209-215
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• 2021

This study is a system development for voice information protection equipment in major meetings and places requiring security. Security performance and stability were secured with information leakage prevention technology through generation of false noise and ultrasonic waves. The cutoff frequency band for blocking the leakage of voice information, which has strong straightness due to the nature of the radio wave to the recording prevention module, blocks the wideband frequency of 20~20,000Hz, and the deception jamming technology is applied to block the leakage of voice information, greatly improving the security. To solve this problem, we developed a system that blocks the recording of a portable smartphone using a battery, and made the installation of a separate device smaller and lighter so that customers do not recognize it. In addition, it is necessary to continuously study measures and countermeasures for efficiently using the output of the anti-recording speaker for long-distance recording prevention.

• The Korean Journal of Pain
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• v.35 no.2
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• pp.224-230
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• 2022

Background: An epidural blood patch (EBP) is a procedure to treat intracranial hypotension that does not respond to conservative treatment. EBPs are commonly repeated when the symptoms persist. In this study, we used a large single-center retrospective cohort and evaluated the factors associated with repeated EBPs. Methods: From January 2010 to December 2020, a total of 596 patients were treated with EBPs for intracranial hypotension. We evaluated the factors associated with repeated EBPs in the entire population, in patients with spontaneous intracranial hypotension (SIH), and in those with available myelographies. Results: In a total of 596 patients, 125 (21.1%) patients required repeated EBPs, and 96/278 (34.5%) in SIH and 29/314 (9.2%) in iatrogenic population. In patients with SIH, international normalized ratio (INR) and cerebrospinal fluid (CSF) leakage on myelographies consistently exhibited significant associations (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.02-1.87; P = 0.043 and OR, 2.18; 95% CI, 1.28-3.69; P = 0.004). In patients with iatrogenic injury, INR and CSF leakage on myelogram did not show difference in repeated EBPs. Conclusions: Repeated EBPs may be more frequently required in patients with SIH. Prolonged INR and CSF leakage were associated with repeated EBPs in patient with SIH. Further studies are needed to determine factors associated with repeated EBP requirements.

• Journal of Platform Technology
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• v.12 no.1
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• pp.67-76
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• 2024

Small and medium-sized enterprises play a fundamental role in the foundation of our country's industry and economy, and most technological innovations occur in small and medium-sized enterprises rather than large corporations. Technology development and innovation are the only way for small and medium-sized enterprises to survive in a fiercely competitive environment, so they focus on it, but interest and investment in technology protection tend to be stingy. As a result, industrial technology leakage accidents occur frequently, and it is difficult to meet improvement measures. When a leak occurs, digital evidence is required to prove criminal activity, but problems such as digital evidence being damaged or deleted due to management loopholes often occur. Therefore, through this study, we aim to design a digital evidence-based countermeasure depending on the type of technology leak accident. We will classify the types of technology leak incidents that actually occurred and study ways to secure digital evidence in the security environment of small and medium-sized businesses that operate internal information leak prevention solutions.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.2
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• pp.1-11
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• 2018

Recently ICT, new technologies such as IoT, Cloud, and Artificial Intelligence are changing the information society explosively. But personal information leakage incidents of consignee's company are increasing more and more because of the expansion of consignment business and the latest threats such as Ransomware and APT. Therefore, in order to strengthen the security of consignee's company, this study derived the checklists through the analysis of the status such as the feature of consignment and the security standard management system and precedent research. It also analyzed laws related to consignment. Finally we found out the relative importance of checklists after it was applied to proposed AHP(Analytic Hierarchy Process) Model. Relative importance was ranked as establishment of an internal administration plan, privacy cryptography, life cycle, access authority management and so on. The purpose of this study is to reduce the risk of leakage of customer information and improve the level of personal information protection management of the consignee by deriving the check items required in handling personal information of consignee and demonstrating the model. If the inspection activities are performed considering the relative importance of the checklist items, the effectiveness of the input time and cost will be enhanced.

• Explosives and Blasting
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• v.28 no.1
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• pp.71-75
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• 2010

A plan of construction of subsea tunnels connecting Korea-Japan and Korea-China have been discussing over the past several ten years. This paper were wrote about the present capacity of our engineer, the cooperation plan of politics and economy. Especially we examined and studied resolution method and technical problem in the construction of Sub-sea tunnel. In terms of excavation technology, Blasting and water resistance technology should be cared considering the status of rock such as fault in the deep sea. After of a construction work, it should be carefully designed and constructed for the fire and leakage management in Tunnel, It should be applied to High Construction Management Professional and Value Management(CVS) etc.

• Journal of Korean Society for Quality Management
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• v.41 no.4
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• pp.649-657
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• 2013

Purpose: In this study, the actual situation of domestic firms vulnerable to industrial security competence will be discussed. And accordingly be discussed for effective response measures. Methods: Using a structured questionnaire by mail, fax, e-mail and fill method was used respondents. By the end of '10 R&D Center, which holds 15,247 companies(population) among the 95% level of confidence, tolerance ${\pm}3%$ p-level corporate type, sector, region extraction method stratified multi-level companies were investigated through the final 1529. Results: The average level of industrial security capabilities 43.8%(out of 100) is very weak, so urgent and positive response measures also need to be investigated sought. Conclusion: we propose the effective management framework and improvement plans to prevent illegal industrial leakage are to be made.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.10 no.1
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• pp.37-43
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• 2014

Nuclear power plants(NPPs) are consisted of power production functions and safety functions preventing leakage of radiation. Operators working in NPPs shall maintain these functions during an operation period through various activities such as improvement & modification, corrective maintenance, preventive maintenance and surveillance test. According to the performance of these work activities, there are configuration changes in NPPs systems. Its changes cause the increase of safety risks(CDF) and plant trip risks. Recently, the importance of risk management is increasing gradually in the operation process of NPPs. Therefore, this paper presents the work management methods using the various risk monitoring systems during power operation and overhaul period. Also this paper suggests the optimum application ways of risk systems for work management.

• The Journal of Korean Association of Computer Education
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• v.8 no.5
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• pp.73-83
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• 2005

Recently, Internet utilization ratio of elementary school students is urgently increasing. On the other hand, elementary school students are not doing personal information management properly in the Internet. As a result, it is causing problem of information leakage. In this paper, we proposed a instructional learning method to teach importance of personal information management to an elementary school student. Proposed method is based on role-play instructional learning method. And applied to the third-year class in elementary school. We show that proposed method is effect in education than traditional teaching method about personal information management's importance.