• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.205-212
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• 2021

In this study, two types of thrust stand modeling were proposed for the design of a thrust stand using flexure. Type A model generate combined load for tangential (thrust) and axial compressive load (self weight). And type B generate combined load for tangential and axial tensile load. The research was done by comparing the influence of the load between the models through a 1D calculation and computational analysis. The 1D calculated value and the computational analysis value were compared for a total of 10 sections and the results were confirmed to be very similar. In order to prove the validity of the analysis results, the equivalent stress was confirmed from the computational analysis of the flexure, and the production of the Type B model was selected from the evaluation of the yield condition (Von-Mises Yield Criterion).

• Food Science and Industry
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• v.49 no.4
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• pp.3-18
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• 2016

The status of Korean food security was analyzed by considering world food situation and food self-sufficiency of Korea, and the hurdles to be solved by science and technology were highlighted. The role of food science and technology in preparing for future food crisis was reviewed in four categories: application of modern biotechnology to increase food production, use of irradiation technology for food storage, food processing technology for rice utilization in particular, and improving food safety regulation system for waste reduction.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.211-217
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• 2020

Molecular mimicry is the most common mechanism that breaches self-tolerance. We previously identified autoantibodies to aquaporin-5 (AQP5) in the sera of patients with Sjögren's syndrome and found that the aquaporin of Prevotella melaninogenica (PmAqp), an oral commensal, is highly homologous to human AQP5. This study aimed to test whether PmAqp can induce anti-AQP5 autoantibodies via molecular mimicry. From the amino acid sequence of PmAqp, an immunizing peptide; i.e., PmE-L, was designed, which contained both the B cell epitope "E" and T cell epitope. C57BL/6 and BALB/c mice were subcutaneously immunized with linear or cyclic forms of PmE-L emulsified in incomplete Freund's adjuvant. The concentrations of the antibodies in sera were measured using enzyme-linked immunosorbent assays. Both linear and cyclic PmE-L induced high levels of antibodies against not only the immunized peptides but also autoantibodies against AQP5E and antibodies against PmE, a Pm homolog of AQP5E. In C57BL/6 mice; however, the cyclic form of PmE-L was more efficient than the linear form in inducing autoantibodies against AQP5E that contained a cyclic epitope. The levels of anti-PmE antibodies and anti-AQP5E autoantibodies showed a strong positive correlation (r = 0.95, p < 0.0005), suggesting molecular mimicry. Collectively, the mice produced anti-AQP5E autoantibodies in response to a PmAqp-derived peptide. This model proved to be useful for studying the mechanisms of autoantibody production by molecular mimicry.

• International Journal of Computer Science & Network Security
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• v.21 no.7
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• pp.35-42
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• 2021

In the article, the authors investigate the economic security system in the conditions of the powers transformation. It is substantiated that economic security acts as a certain system that includes components and at the same time acts as a subsystem of the highest order. It is determined that the economic security system of regions acting as a system has its subsystems, which include: production, financial, environmental, innovation, investment and social subsystems. The parameters of the economic security system include relative economic independence, economic stability and self-development of economic systems, and it is proved that an important feature of economic security in addition to its systemic nature is multi-vector. It is substantiated that the monitoring of ensuring the economic security system of the development of economic systems of different levels in the conditions of the powers transformation should contain the analysis of social, economic and ecological development of regions; spheres of possible dangers of the development of regional economic systems; the nature of the threats; the degree of the possibility of threats; time perspective of economic development threats; possible consequences of losses for economic entities; the impact of threats to the object of the economic entities' activity; possible asymmetry of economic development of regional economic entities. Possible threats as a consequence of the powers transformation have been identified. A PEST analysis of the impact of factors of different nature on economic security and the development of regional economic systems in the powers transformation is carried out. A recurrent ratio is proposed for the economic security system in the conditions of the powers transformation.

• International Journal of Contents
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• v.18 no.2
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• pp.1-17
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• 2022

As of September 2021, COVID-19 is still seriously impacting people globally. To better control the epidemic, the Chinese government adopted a nationwide quarantine policy at the early stage of the discovery of COVID-19, which has significantly changed people's production and life. China's Douyin app (International version: TikTok) is an extremely influential entertainment and social tool. During COVID-19, a large number of short videos about COVID-19 appeared. Publishers included government agencies, professionals, and self-media. The content released has made Douyin a tool for people to receive COVID-19 information in addition to entertainment and social functions. This is a quantitative study. By exploring the impact of the Douyin app on Chinese college students during COVID-19, this study provides suggestions from the level of social media such as TikTok to enable Korea's epidemic prevention to be more effective. This study established variable questions such as Douyin's information perceived value, information usage channels, information awareness, anti-epidemic policy attitude, trust of public institution and preventive behavioral intention, and conducted a questionnaire survey. Using SPSS to analyze the obtained data, this study found that: 1. The short video information usage channels about COVID-19 in Douyin have a positive impact on the audience's information awareness; 2. The information perceived value in Douyin has a positive impact on the audience's information awareness; 3. Information awareness and trust of public institution in Douyin have a positive impact on the audience's anti-epidemic policy attitude; 4. Information awareness and trust of public institutions in Douyin have a positive impact on the audience's preventive behavioral intention; 5. The audience's anti-epidemic policy attitude has a positive effect on preventive behavioral intention.

• International Journal of Contents
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• v.18 no.2
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• pp.47-57
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• 2022

e-Learning content can be defined as digital content to achieve educational goals. Since it is an educational material that can be distributed in offline, online, and mobile environments, it is important to create content that meets the learner's education environment and educational goals. In particular, if the learner is a public official, the vision, philosophy, and characteristics of each local government must reflect. As non-face-to-face online education expands further due to the COVID-19 pandemic, local governments that have relied on onsite education in the past urgently require developing strong basic competency education and special task competency content that reflect regional characteristics. Such e-learning content, however, hardly exists and the ability to independently develop them is also insufficient. In this circumstance, this case study describes the process of self-production of e-learning content suitable for Busan's characteristics by the Human Resource Development (HRD) Institute of Busan City, a local government. The field of instructional design and instructional technology is always evolving and growing by blending technological innovation into instructional platform design and adapting to the changes in society. Busan HRD Institute (BHI), therefore, tried to implement blended learning by developing content that reflected the recent trend of micro-learning in e-learning through a detailed analysis. For this, an e-learning content developer with certain requirements was selected and contracted, and the process of developing content through a collaboration between the client and developer was described in this study according to the ADDIE model of Instructional Systems Development (ISD).

• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.148-154
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• 2022

As the 4th industrial age approaches, the demand for semiconductors is increasing enough to be used in all electronic devices. At the same time, semiconductor technology is also developing day by day, leading to ultraprecision and low power consumption. Semiconductors that keep getting smaller generate heat because the energy density increases, and the generated heat changes the shape of the semiconductor package, so it is important to manage. The temperature change is not only self-heating of the semiconductor package, but also heat generated by external damage. If the package is deformed, it is necessary to manage it because functional problems and performance degradation such as damage occur. The package burn in test in the post-process of semiconductor production is a process that tests the durability and function of the package in a high-temperature environment, and heat dissipation performance can be evaluated. In this paper, we intend to review a new material formulation that can improve the performance of the adapter, which is one of the parts of the test socket used in the burn-in test. It was confirmed what characteristics the basic base showed when polyamide, a high-molecular material, and alumina, which had high thermal conductivity, were mixed for each magnification. In this study, functional evaluation was also carried out by injecting an adapter, a part of the test socket, at the same time as the specimen was manufactured. Verification of stiffness such as tensile strength and flexural strength by mixing ratio, performance evaluation such as thermal conductivity, and manufacturing of a dummy device also confirmed warpage. As a result, it was confirmed that the thermal stability was excellent. Through this study, it is thought that it can be used as basic data for the development of materials for burn-in sockets in the future.

• Journal of the International Relations & Interdisciplinary Education
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• v.2 no.1
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• pp.29-41
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• 2022

In recent years, visual design has become an emerging industry that creates production value in various countries, and visual design teachers have become a key factor affecting the development of designers and even the trend of the design industry. Therefore, the requirements for the ability of visual design teachers have become particularly important. This study takes the visual communication teachers in colleges and universities as the research object. Focus on the composition of competencies that teachers have when performing their duties. First of all, through document sorting, it is based on the five aspects of knowledge ability, teaching ability, practical ability, management ability and professional ethics. A Likert scale questionnaire was developed on the evaluation of visual design teachers' competencies by interviewing 10 visual design industry experts and conducting two Delphi method interviews. This research refers to the relevant literatures such as curriculum research and teaching objective research of design major, and discusses the evaluation standards of visual design teachers' abilities in colleges and universities. Expert interviews have sorted out 12 criteria and 36 sub-criteria about visual design teachers' abilities, and verified their rationality through expert return visits. The establishment of this evaluation standard provides a certain theoretical basis for visual design teachers' ability evaluation and self-cognition.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.102-110
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• 2023

The MATS(Missile Assembly Test Set) is manufactured and used to check the function of the missile during the period of development for the guided missile system, and the requirements for power and communication are managed for equipment production. The MATS developer implements software according to the proposed communication standard to guarantee the reliability of the data that communicates with the guided missile. The test bed is built and self-performance evaluation is performed after implementation. And the verification process is performed using the standard equipment. The characteristics of periodic delay for data transmission must be reflected when building a test bed. This paper describes a test bed construction method for data processing with periodic delay. Also This paper compares and evaluates the performance by changing the previously designed algorithm.

• Journal of Surface Science and Engineering
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• v.56 no.3
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• pp.208-218
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• 2023

Photocatalysts are advanced materials which accelerate the photoreaction by providing ordinary reactions with other pathways. The catalysts have various advantages, such as low-cost, low operating temperature and pressure, and long-term use. They are applied to environmental and energy field, including the air and water purification, water splitting for hydrogen production, sterilization and self-cleaning surfaces. However, commercial photocatalysts only absorb ultraviolet light between 100 and 400 nm of wavelength which comprises only 5% in sunlight due to the wide band gap. In addition, rapid recombination of electron-hole pairs reduces the photocatalytic performance. Recently, studies on blackening photocatalysts by laser, thermal, and plasma treatments have been conducted to enhance the absorption of visible light and photocatalytic activity. The disordered structures could yield mid-gap states and vacancies could cause charge carrier trapping. Herein, liquid phase plasma (LPP) is adopted to synthesize Ag-doped black ZnO for the utilization of visible-light. The physical and chemical characteristics of the synthesized photocatalysts are analyzed by SEM/EDS, XRD, XPS and the optical properties of them are investigated using UV/Vis DRS and PL analyses. Lastly, the photocatalytic activity was evaluated using methylene blue as a pollutant.