• The Journal of Korean Academy of Prosthodontics
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• v.60 no.1
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• pp.71-79
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• 2022

Excessive crown height space increases can cause crestal bone loss and screw loosening after prosthesis is placed. Milled bar and implant overdenture can be used as a treatment method for partially edentulous patients who have severe alveolar bone loss and excessive crown height space. Milled bar can provide primary splinting effect and stability between implants. Also, milled bar with additional retention device such as Advanced Dental Device-Treatment Of Choice (ADD-TOC) and magnet can provide additional retention force for implant overdenture. In this case, the patient has a partially edentulous mandible that has severe alveolar bone loss and multiple number of teeth loss after excision due to leiomyosarcoma. Because of the long-term loss of mandibular molars, the opposing teeth were extruded. Maxillary left molars were corrected to the occlusal plane through molar intrusion, and mandibular left molar region were treated with implant overdenture, using milled bar with ADD-TOC and magnet after implant placement. The clinical result was satisfactory on the aspect of esthetic and masticatory function.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.492-498
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• 2022

Process control systems used in most domestic petrochemical corporates today are based on the Windows platforms. As technology leans toward opened environment, the exposure risk of control systems is increasing. However, not many companies are preparing for various cyberattacks due to lack of awareness and misunderstanding of cyber intrusion. This study investigated the extent of how much exposed the petrochemical process control system is to security threats and suggested practical measures to reduce OT cybersecurity vulnerabilities. To identify the cyber threat status of process control systems, vulnerabilities of the Windows platform, a principal cyber threat factor, have been analyzed. For research, three major DCS providers in Korea and the discontinuation of Windows platform of 635 control systems were investigated. It was confirmed that 78% of the survey subjects were still operating in the discontinued windows platforms, and those process control systems were operated in a state vulnerable to cyber intrusions. In order to actively cope with these cyber threats, legal regulations such as designation of critical infrastructure for major petrochemical facilities which is implemented in advanced countries such as the United States are needed. Additionally, it is necessary to take the initiative in eradicating security threats to the process control systems by aggressively introducing security solutions provided from existing DCS suppliers. This paper was submitted to Professor Ko JaeWook's retirement anniversary issue.

• Journal of Internet Computing and Services
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• v.23 no.4
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• pp.87-94
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• 2022

Recently, with the development of information and communication infrastructure, the number of Internet access devices is rapidly increasing. Smartphones, laptops, computers, and even IoT devices are receiving information and communication services through Internet access. Since most of the device operating environment consists of web (WEB), it is vulnerable to web cyber attacks using web shells. When the web shell is uploaded to the web server, it is confirmed that the attack frequency is high because the control of the web server can be easily performed. As the damage caused by the web shell occurs a lot, each company is responding to attacks with various security devices such as intrusion prevention systems, firewalls, and web firewalls. In this case, it is difficult to detect, and in order to prevent and cope with web shell attacks due to these characteristics, it is difficult to respond only with the existing system and security software. Therefore, it is an automated defense system through the collection and analysis of web shells based on artificial intelligence machine learning that can cope with new cyber attacks such as detecting unknown web shells in advance by using artificial intelligence machine learning and deep learning techniques in existing security software. We would like to propose about. The machine learning-based web shell defense system model proposed in this paper quickly collects, analyzes, and detects malicious web shells, one of the cyberattacks on the web environment. I think it will be very helpful in designing and building a security system.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.191-199
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• 2021

In this study, the correlation between the influencing factors on corrosion and Half Cell Potential(HCP) measurement was analyzed considering the three levels of W/C ratio, cover depth, and chloride concentration. The HCP increased with enlarged cover depth, so it was confirmed that the increment of cover depth was effective for control of corrosion. Based on the criteria, the case of 60mm cover depth showed excellent corrosion control with under -200mV, indicating increase of cover depth is an effective method for reducing intrusion of external deterioration factors. When fresh water was injected to the upper part of specimens, very low level of HCP was monitored, but in the case that concentrations of chloride were 3.5% and 7.0%, HCP dropped under -200mV. In addition, the case with high volume of unit binder showed lower HCP measurement like increasing cover depth. Multiple regression analysis was performed to evaluate the correlation between the corrosive influence factors and HCP results, showing high coefficient of determination of 0.97. However, there were limitations such as limited number of samples and measuring period. Through the additional corrosion monitoring and chloride content evaluation after dismantling the specimen, more reasonable prediction can be achieved for correlation analysis with relevant data.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1011-1020
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• 2022

Previous studies for the assessment of submarine groundwater discharge (SGD) were perfomed for areas where a large amount of SGD was observed. Newly developed assessment methods were proposed that was based on an analytic solution using sharp interface model. The proposed mathematical equations used the existing observed groundwater level and hydrogeological data of Jeju Island as input data. The quantitatively assessed FSGD values were compared to the basin-scale recharge estimation values in Seong-San area in eastern Jeju. As a result of the study, it was estimated that the amount of FSGD in the Seongsan area ranges from about 2.65 to 9.15% of the amount of areal-recharge. Through the analysis of the FSGD combined with the analytic model, it is to be provided as a scientific tool to establish a more reasonable coastal water resource management plan.

• Korean Journal of Culture and Social Issue
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• v.27 no.3
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• pp.325-350
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• 2021

The purpose of this study was to examine the mediating effect of the parent-adolescent career congruence process in the association between the parent-adolescent relationship and career identity of South Korean college students. In particular, we investigated which kind of career congruence process mediates the positive effect of the interdependent parent-adolescent relationship (in support of emotional bond and filial piety) and the independent parent-adolescent relationship (in support of independence and autonomy) on career identity. Data of 509 college students were analyzed for this study, and parallel multiple mediation analysis was performed. As a result, the complementary and attunement congruence process fully mediated the relationship between parent-adolescent affective bonding and career identity. Authoritative filial piety had a negative direct effect on career identity, but a positive indirect effect by mediating the complementary and attunement congruence process. The mediation analysis showed that both complementary and attunement congruence process fully mediated the association between independent parent-adolescent relationship and career identity. However, family intrusion had only a negative direct effect on career identity. On the other hand, the supplementary congruence process did not have significant mediating effects between all types of parent-adolescent relationships and career identity. Also, the supplementary congruence process had a negative direct effect on career identity. Based on these results, we discussed culturally universal and culturally specific characteristics of the relationship between parent-adolescent relationships and career identity, along with the limitations and recommendations for future research.

• Membrane Journal
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• v.33 no.4
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• pp.191-200
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• 2023

Polyethersulfone (PES) is a widely employed membrane material for water and industrial purification applications owing to its hydrophilicity and ease of phase separation. However, PES membranes and filters prepared using the nonsolvent induced phase separation method often encounter significant flux decline due to pore clogging and cake layer formation on the dense membrane surfaces. Our investigation revealed that tight microfiltration or loose ultrafiltration membranes can be subject to physical fouling due to the formation of a dense skin layer on the bottom side caused by water intrusion to the gap between the shrank membrane and the substrate. To investigate the effect of the bottom surface porosity on membrane fouling, two membranes with the same selective layers but different sub-layer structures were prepared using single and double layer casting methods, respectively. The double layered PES membrane with highly porous bottom surface showed high flux and physical fouling tolerance compared to the pristine single layer membrane. This study highlights the importance of physical optimization of the membrane structure to prevent membrane fouling.

• Journal of the Korea Institute of Building Construction
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• v.23 no.3
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• pp.221-229
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• 2023

This research aimed to conduct an empirical assessment of the penetration of chloride and sulfate ions into mortar sections using an anion exchange membrane(AEM) and laser-induced breakdown spectroscopy(LIBS). The study involved a simultaneous ion chromatography(IC) analysis and LIBS analysis performed on mortars immersed in varying concentrations of chloride and sulfate. The findings revealed that at the wavelengths specific to Chloride(837.59nm) and Sulfur(921.30nm), the LIBS intensity achieved using AEM surpassed that obtained with a paper substrate at equivalent penetration concentrations. A robust correlation was confirmed between LIBS intensity and chloride ion concentration. Furthermore, when juxtaposed with IC analysis concentration outcomes at identical depths, the AEM displayed a higher intensity. The research noted an enhancement in LIBS intensity and a diminution in errors within the low-concentration section when deploying AEM. However, for the Sulfur wavelength of 921.3nm, there remains a need to augment the sensitivity of the LIBS signal within the low-concentration section in future studies. The findings underscore the potential of employing AEM and LIBS for precise analysis of chloride and sulfate ion penetration into mortar sections. This strategy can aid in bolstering assessment precision and mitigating errors, particularly in regions with low concentrations. It is recommended to further research and develop methods to amplify the sensitivity of the LIBS signal for sulfur detection in low-concentration sections. In sum, the study accentuates the significance of employing advanced techniques like AEM and LIBS for efficacious and precise analysis in the domain of mortar section assessment.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.5
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• pp.303-314
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• 2018

In the past few years, government agencies and corporations have succumbed to stealthy, tailored cyberattacks designed to exploit vulnerabilities, disrupt operations and steal valuable information. Security Information and Event Management (SIEM) is useful tool for cyberattacks. SIEM solutions are available in the market but they are too expensive and difficult to use. Then we implemented basic SIEM functions to research and development for future security solutions. We focus on collection, aggregation and analysis of real-time logs from host. This tool allows parsing and search of log data for forensics. Beyond just log management it uses intrusion detection and prioritize of security events inform and support alerting to user. We select Elastic Stack to process and visualization of these security informations. Elastic Stack is a very useful tool for finding information from large data, identifying correlations and creating rich visualizations for monitoring. We suggested using vulnerability check results on our SIEM. We have attacked to the host and got real time user activity for monitoring, alerting and security auditing based this security information management.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.7
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• pp.9-16
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• 2016

As life in a rapidly changing Internet age at home and abroad, large amounts of information are being used medical, financial, services, etc. Accordingly, especially hospitals, is an invasion of privacy caused by leakage and intrusion of personal information in the system in medical institutions, including clinics institutions. To protect the privacy & information protection of personal health medical information in medical institutions at home and abroad presented by national policies and de-identification processing technology standards in accordance with the legislation. By comparative analysis in existing domestic and foreign institutional privacy and de-identification technique, derive a advanced one of pseudonymization and anonymization techniques for destination data items that fell short in comparison to the domestic laws and regulations, etc. De-identification processing technology for personal health information is compared to a foreign country pharmaceutical situations. We propose a new de-identification techniques by reducing the risk of re-identification processing to enable the secondary use of domestic medical privacy.