• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.374-381
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• 2019

A conventional approach for the treatment of long-span edentulous areas is the use of removable dentures. However, placing implants in these areas results in superior functional outcomes by increasing the stability, support, and resistance of the prostheses and improving the masticatory efficiency. Treatment modalities utilizing implants can be further classified into either removable or fixed-type prostheses. Several factors such as the amount of alveolar bone resorption, inter-arch relationship, patient preferences, and socioeconomic status should be considered when determining the appropriate treatment approach. Monolithic zirconia has been considered a suitable material for implant-supported fixed dental prosthesis, because of the drastic improvement in its mechanical properties. It exhibits fewer incidences of fracture and chipping of the prostheses, and has greater bulk of material than metal-ceramic crowns and zirconia-veneered ceramics. Moreover, highly translucent monolithic zirconia is also available in the market, and its application is gradually increasing for anterior tooth rehabilitation. The present report describes a patient who underwent full-mouth rehabilitation with fixed dental prostheses (eight upper and three lower implant placements). All teeth, except bilateral mandibular canines and left mandibular first and second premolars, were extracted after the diagnosis of generalized chronic moderate-to-advanced periodontitis of the remaining teeth. The patient reported satisfactory esthetic and functional outcomes during the one-year follow-up visit.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.9
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• pp.217-224
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• 2019

Recently, sensor networks are built and used on many kinds of fields such as home, traffic, medical treatment and power grid. Sensing data manipulation on these fields could be a serious threat on property and safety. Thus, a proper way to block sensing data manipulation is necessary. In this paper, we propose IoT(Internet of Things) sensing data validation mechanism based on data obfuscation and variance analysis to remove manipulated sensing data effectively. IoT sensor device modulates sensing data with obfuscation function and sends it to a user. The user demodulates received data to use it. Fake data which are not modulated with proper obfuscation function show different variance aspect with valid data. Our proposed mechanism thus can detect fake data by analyzing data variance. Finally, we measured data validation time for performance analysis. As a result, block rate for false data was improved by up to 1.45 times compared with the existing technique and false alarm rate was 0.1~2.0%. In addition, the validation time on the low-power, low-performance IoT sensor device was measured. Compared to the RSA encryption method, which increased to 2.5969 seconds according to the increase of the data amount, the proposed method showed high validation efficiency as 0.0003 seconds.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.276-286
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• 2021

General high fluidity concrete is the area of high strength concrete with a high amount of cement to secure the required fluidity and workability. Since most of the concrete structures currently used have normal strength, there is a limit to the practical expansion and practicality of use. Thus it is necessary to develop normal strength-high fluidity concrete with low binders that can be used not only in general buildings but also in special buildings, and can greatly reduce construction time and save labor costs. This requires to develop and apply the polycarboxylate-based superplasticizer. In this study, PCE was prepared for each combination of starting materials(WR, HB, RT) and the rheological properties of cement paste were analyzed using ringflow cone and a rotary viscometer. As a result, when PCE with a combination of WR 80%, HB 6.5%, and RT 13.5% was applied, the yield stress can be minimized while securing the plastic viscosity at level of the normal strength. In addition, high fluidity due to the high dispersion effect was confirmed.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.391-402
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• 2021

Purpose: By categorizing opinions by subject in the safety certification ecosystem, we want to identify weaknesses in system operation and suggest improvement plans so that the safety certification system can have quick resilience against future variability. Method: Through literature research and data analysis, similar domestic and foreign safety certifications and related cases, as well as the current status of international standards and national standards, etc. were confirmed, and a fact-finding survey was conducted for each stakeholder in the safety certification ecosystem, and problem types and improvement measures were established. Result: We conduct a fact-finding survey of the overall system, such as quality satisfaction with safety certification target products, obstacles in the development, manufacturing and use process, and safety certification-related improvements, targeting workplaces that manufacture, import or use safety certification target machines By discovering and categorizing problems and weaknesses in system operation, detailed implementation tasks were derived to establish improvement directions and improve operability. Conclusion: For the advancement and internationalization of the safety certification system, it is necessary to efficiently carry out the detailed promotion tasks derived from this study. In addition, in order to strengthen the resilience to the variability of the safety certification ecosystem, the operating system of a virtuous cycle structure by improving the mutual relationship between each subject construction is considered important.

• Journal of the Society of Disaster Information
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• v.15 no.2
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• pp.223-238
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• 2019

Purpose: This study aims at exploring implications of discourse and social practice produced by various stakeholders in politics, economy and society to provide useful material for effective disaster response in South Korea. Method: Applying the Critical Discourse Analysis model of Fairclough, this study analyzes the newspaper articles of three domestic press companies mainly about the November 2017 Pohang earthquake. Results: As a result, first, the three media companies point out the low effectiveness of disaster response manuals and evacuation training. Second, strengthening shelter services and expanding support for the victims are important for recovery from the earthquake. Third, to prevent the future damages, they suggest the implementation efforts to improve the seismic design and short message service based disaster alert system. Conclusion: Based on the findings, this study suggests to improve the practicality and effectiveness of disaster prevention measures, establish an organic and integrated disaster response system, emphasize the roles and participation of citizens, check the responsibility of experts, and make the media to form sound discourse on disaster response.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.8
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• pp.181-190
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• 2019

The purpose of this study is to verify the effects of information system quality on business performance (net benefit) in the Korean public informatization business and to verify whether the user has mediating role in the relationship between information system quality and net benefit. In order to prepare empirical tests, factor analyses was conducted and the validity and reliability of the variables were confirmed to be acceptable. The research hypotheses were tested by regression analyses. The mediating effects as well as the main effects were analyzed by SPSS statistical program. The results show that the higher the quality of the information system becomes, the higher the usability by the users of the system increases. Also, it was found that the users had more positive effect on the net benefit of the public informatization project. In addition, it was confirmed that there was a partial mediating effect by the users on the relationship between information system quality and the benefits. The results of the research suggests that we establish a management system to improve the business performance efficiently according to the priorities of detailed success factors from the viewpoint of the public information business, and the users who use the information system quality and system.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.135-141
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• 2020

The silica aerogels with benzene-bridged were designed to have uniform network structure, ordered pore structure, improved mechanical properties and excellent textural properties. Adding organic to enhance the mechanical properties of silica aerogels is a common method, but textural properties of aerogels with organic are reduced due to the organic-inorganic phase separation. In this paper, we use a simple and low-cost method to increase mechanical properties while maintaining textural properties of SiO2 aerogels. Two types of benzene-bridged precursors were prepared to study the effect of the number of hydroxyl band on the textural and mechanical properties. The porous silica aerogel was prepared by a simple, cost effective and pollution-free sol-gel method. This method does not require additional silylating reagents. The benzene-bridged silica aerogel samples prepared had excellent textural properties, high specific surface area (1,326 ㎡/g), porous structure and hydrophobicity (>140°). The mechanical strength of 2T4 is more than 5 times that of pure silica aerogel.

• The Journal of Society for e-Business Studies
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• v.26 no.4
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• pp.37-52
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• 2021

Due to the spread of COVID-19, it is rapidly changing from face-to-face to non-face-to-face work environments and is changing to a digital work environment that can be accessed anytime, anywhere, providing convenience to all lives. However, the number of breaches, personal information leakage, and technology leakage targeting SMEs that are vulnerable to security continues to increase. Accordingly, the government has been continuously promoting the information security consulting support project for SMEs every year since 2014. Therefore, this study intends to develop a performance model and measurement methodology for continuous and more systematic support and efficient management of information protection support projects in consideration of the importance of information security for SMEs. It is intended to be used as basic data when setting future operational directions and goals. The main method of this study is to derive performance models and indicators for SME information security support projects based on domestic literature, case studies, and survey results, utilize expert advice to verify the developed performance measurement indicators, and use pilot-test questionnaires. Conduct evaluation through surveys. Based on the verified indicators, we would like to present a performance model and measurement index for the information security support project for SMEs.

• Korean Journal of Construction Engineering and Management
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• v.23 no.2
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• pp.85-94
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• 2022

Construction industry is facing difficult challenges in terms of productivity, manpower, and industrial accidents. Currently, along with the 4th Industrial Revolution, various high-tech technologies are emerging, and efforts are being made to solve the problem by applying the technologies related to the 4th Industrial Revolution to the construction industry. As part of these efforts, research is being conducted to develop a construction equipment control system to increase productivity and safety at earthworks sites where many and various types of construction equipment are involved, and the system needs a function to increase productivity by optimizing the moving path of construction equipment. In the case of trucks, the location of the temporary road must be optimized in order to optimize the path of movement in the construction site. However, only matters related to the quality standard of temporary roads have been suggested so far, and there is no standardized process for efficiently determining the location of temporary roads. In this paper, the factors and its importance related to the location of the temporary road were identified through field surveys and interviews with experts, and a method for determining the location of the temporary road was presented. It was confirmed that the suggested method through a case study could improve the productivity of earthwork.

• Trans-
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• v.13
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• pp.35-58
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• 2022

This study predicts the paradigm shift that the development of artificial intelligence technology will bring to the production of music content, and suggests that works created through collaboration between artificial intelligence and humans can have artistic value as finished products. Anyone can easily produce music content using artificial intelligence composition programs, and it has become an opportunity to inspire artists with various attempts and creative ideas. Although artificial intelligence technology provides convenience in human life and benefits a lot in the efficient aspect of work, it is difficult to escape the perception of data-based pattern music in the art field so far. Pattern music with many quantitative elements is not recognized as a complete creation due to the absence of abstract symbolism or meaning pursued by art. However, it predicts that if qualitative elements such as emotions and creativity are given to artificial intelligence music through human collaboration, it can be recognized as a complete work of art. The development of artificial intelligence technology increases access to culture and art from the public, and it can be expected that anyone can enjoy it as well as aesthetic experiences. In addition, various contents can be produced by improving individual digital literacy, and it is an opportunity to share and communicate with others. As such, artificial intelligence technology serves as a medium connecting the public with culture and art, and is narrowing the gap between humans and technology through art activities. Along with this cultural phenomenon, we predict the possibility of research on the production of artificial intelligence music contents with artistic value and the development of various convergence and complex art contents using artificial intelligence technology in the future.