• Information Systems Review
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• v.18 no.2
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• pp.199-223
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• 2016

As social networking services (SNS) become widely used tools for maintaining social relationships, people use SNS to express themselves online. Users are free to form multiple characters in SNS because of online anonymity. This phenomenon causes SNS users to easily demonstrate multiple personas that are different from their identities in the real world. Therefore, this study focuses on online multi-personas that establish multiple fake identities in the SNS environment. The main objective of this study is to investigate factors that affect online multi-personas. Fake online identities can have various negative consequences such as cyber bullying, cyber vandalism, or antisocial behavior. Since the boundary between the online and offline worlds is fading fast, these negative aspects of online behavior may influence offline behaviors as well. This study focuses on teenagers who often create multi-personas online. According to previous studies, personal identities are usually established during a person's youth. Based on data on 664 teenage users, this study identifies four emotional factors, namely, closeness with others, relative deprivation, peer pressure and social norms. According to data analysis results, three factors (except closeness with others) have positive correlations with users' multi-personas. This study contributes to the literature by identifying the factors that cause young people to form online multi-personas, an issue that has not been fully discussed in previous studies. From a practical perspective, this study provides a basis for a safe online environment by explaining the reasons for creating fake SNS identities.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.629-634
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• 2017

In the case of the UHP (Ultra high performance) tire that the demand has increased rapidly, compared with the commonly used tire, severe deformation has been observed because of the low aspect ratio. When repeated deformations are applied to the sidewall rubber, accumulated fatigue damage may cause fatigue failure. Thus, the evaluation of the durability of the tire sidewall rubber has become a very important issue to prevent accidents that occur while the vehicle is running. However, the research and design criteria for the durability performance of the tire sidewall rubber hardly exist. In this study, we suggest a lifetime prediction formula using strain energy density obtained by performing tensile tests and fatigue tests on two different kinds of the tire sidewall compounds. Additionally, the applicability of our findings for low fuel consumption tires was reviewed by converting the fatigue life of the sidewall rubber into the expected mileage of the tire.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.2
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• pp.134-145
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• 2004

With rapid growth in the amount of data transferred on the Internet, traditional storage systems have reached the limits of their capacity and performance. SAN (Storage Area Network), which connects hosts to disk with the Fibre Channel switches, provides one of the powerful solutions to scale the data storage and servers. In this environment, the maintenance of data consistency among hosts is an important issue because multiple hosts share the files on disks attached to the SAN. To preserve data consistency, each host can execute the disk I/O whenever disk read and write operations are requested. However, frequent disk I/O requests cause the deterioration of the overall performance of a SAN cluster. In this paper, we introduce a SANtopia global buffer manager to improve the performance of a SAN cluster reducing the number of disk I/Os. We describe the design and algorithms of the SANtopia global buffer manager, which provides a buffer cache sharing mechanism among the hosts in the SAN cluster. Micro-benchmark results to measure the performance of block I/O operations show that the global buffer manager achieves speed-up by the factor of 1.8-12.8 compared with the existing method using disk I/O operations. Also, File system micro-benchmark results show that SANtopia file system with the global buffer manager improves performance by the factor of 1.06 in case of directories and 1.14 in case of files compared with the file system without a global buffer manager.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.830-837
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• 2015

Space debris has been a major issue recently for the space-active nations because its growing population is expected to increase the collision risk with operational satellites. Radar and electro-optical system has been used for space debris surveillance, which may cause unnecessary anti-collision manoeuvers due to their low tracking accuracy. So an additional tracking system is required to improve the predicted orbit accuracy and then to jude the anti-collision maneouvers more efficiently. The laser tracking system has been considered as an alternative to decrease these unnecessary manoeuvers. Korea Astronomy and Space Science Institute has been developing a space object laser tracking system which is capable of laser tracking for satellites with retro-reflectors and for space debris using high power laser, and satellite imaging using adaptive optics. In this study, the tracking capability is analyzed for space debris using high power laser based on link budget, false alarm probability and signal detection probability.

• Journal of Life Science
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• v.23 no.1
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• pp.143-156
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• 2013

Due to the high incidence of cancer and cancer-related mortality in Korea, there is increased concern and psychological anxiety about this disease, leading to increasing numbers of cancer studies. Despite these, the trend of the cancer incidence rate has shown a significant increase. The detection of colorectal cancer, which has a high incidence rate, often tends to be delayed, causing a high mortality rate. Therefore, the prevention of colorectal cancer has become an important emergent issue. The cause of this cancer has not been confirmed. However, it may be attributable to westernized dietary patterns, which include consuming a high quantity of red meat. Consumption of dietary fiber promotes the production of butyrate short-chain fatty acids by enteric bacteria. In the treatment of cancer, anticancer medications have been shown to lead to the apoptosis of tumor cells, and a strong relationship between apoptosis mechanisms of tumor cells and cancer treatment has been confirmed. The results of many studies have confirmed that butyrate can directly promote the apoptosis of colorectal cancer cells. Therefore, increased consumption of dietary fiber, which promotes the production of butyrate shortchain fatty acids, can be expected to have an effect on the prevention and treatment of colorectal cancer.

• Journal of the Korean Society for information Management
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• v.28 no.3
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• pp.141-162
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• 2011

This research was conducted to analyze the actual condition of data related to Korea shown in the catalog of 15 countries. This study was to compare the subject characteristics of Korea-related subject heading, record collection, and the characteristics of several subject heading, which has been a major issue. The results are as follows. To begin with, Korea-related record in most other national libraries runs absolutely short except for some countries like United States. Korea-related record is generally 2 to 3 times less than Japan related record. Second, referring to the subject distribution in sub criteria of Korea-related record, subject related to 'history' and 'economy' is shown in the highest rate. Considering that 'Korean war' shows the highest rate in Italy and Canada, we can consider that this may cause the distortion of the perception of Korea. Third, in the case of Korea-related record, the record of South Korea is 1.5 to 5 times more than that of North Korea, except for some countries like United States. Forth, regarding the subject headings, the terms such as 'Taekwondo', 'Kimchi', 'Tok-do', 'Tong-hae' have different meanings in different countries. However, these terms agree to LCSH in most countries except for neighboring countries. Fifth, in case of China and Japan, the subject headings in reference to political and historical position are raising some problems.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.104-111
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• 2016

The steel frame modular housing of which the research and development has been actively carried out recently cannot be constructed through monolithic placement like the reinforced concrete deck of general structure due to the characteristics of construction method of production in the factory and assembly on the site. And floor vertical vibration and deflection caused by inhabitants' activities may become an important issue in the aspect of usability evaluation due to a decrease in the section size of member, a decrease in weight, and so on. Therefore, this study evaluated the vibration performance of deck by using formula of AISC Design Guide 11(hereinafter AISC formula) which was practically used in general for modules where a stud was and wasn't installed at the center of beam in the longitudinal direction in the modular housing to be studied, and examined the applicability of AISC formula through comparison with the results of analysis using a general-purpose analysis program. On the basis of this, a structural cause for an error to occur between analysis result and AISC formula in the deck of module in which a stud was installed was analysed, and measures for considering this were suggested. Besides, an analysis model with the variables of measures for improving the floor vibration performance of modular housing to be studied was established. And measures having excellent vibration performance and economic feasibility were suggested through vibration response analysis and economic evaluation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.93-97
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• 2007

Even in the moderately concentrated anionic surfactant system, some special encapsulation method can shield the papain enzyme from proteolytic attacks. The stabilization of enzyme has been a major issue for successful therapies. In this study, we first stabilized an enzyme, papain in the microcapsules by using polyols, polyethyleneglycol (PEG), poly-propyleneglycol (PPG), and PEG-PPG-PEG block copolymer. In the analysis of EDS and CLSM, it was demonstrated that polyols are effectively located in the interface of papain and polymer. Polyols located in the interface had an ability to buffer the external triggers by hydrophobic partitioning, preventing consequently the catalytic activity of papain in the micro-capsules. Second. we introduced multi-layer capsulation methods containing ion complex. Such a moderately concentrated anionic surfactant system as wash-off cleansers, surfactants and waters can cause instability of entrapped enzymes. Surfactants and water in our final products swell the surface of enzyme capsules and penetrate into the core so easily that we can not achieve the effect of enzyme, papain. In this case, the ion complex multi-layer capsule composed of sodium lauroyl sarcosinate and polyquaternium-6 could effectively prevent water from penetration into the core enzyme, followed by in vivo test, and evaluate the stratum corneum (SC) turn-over speed.

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.668-674
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• 2019

Objectives: Modern people spend most of their day indoors. As the health impact of radon becomes an issue, public interest also has been growing. The primary route of potential human exposure to radon is inhalation. Long-term exposure to high levels of radon increases the risk of developing lung cancer. Radon exposure is known to be the second-leading cause of lung cancer, following tobacco smoke. This study measures the indoor radon concentrations in detached houses in area A of Chungcheongbuk-do Province considering the construction year, cracks in the houses, the location of installed detectors, and seasonal effects. Methods: The survey was conducted from September 2017 to April 2018 on 1,872 private households located in selected areas in northern Chungcheongbuk-do Province to figure out the year of building construction and the location of detector installed and identify the factors which affect radon concentrations in the air within the building. Radon was measured using a manual alpha track detector (Raduet, Hungary) with a sampling period of longer than 90 days. Results: Indoor radon concentrations in winter within area A was surveyed to be 168.3±193.3 Bq/㎥. There was more than a 2.3 times difference between buildings built before 1979 and those built after 2010. The concentration reached 195.4±221.9 Bq/㎥ for buildings with fractures and 167.2±192.4 Bq/㎥ for buildings without fractures. It was found that detectors installed in household areas with windows exhibited a lower concentration than those installed in concealed spaces. Conclusion: High concentrations of indoor radon were shown when there was a crack in the house. Also, ventilation seems to significantly affect radon concentrations because when the location of the detector in the installed site was near windows compared to an enclosed area, radon concentration variation increased. Therefore, it is considered that radon concentration is lower in summer because natural ventilation occurs more often than in winter.

• Journal of National Security and Military Science
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• s.4
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• pp.83-118
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• 2006

This study is to develop digital leadership in a field of national defense. Today, korean society is facing the crisis of national security. But national defense leadership is not show in the circumstance of national security crisis. As you know, national defense leadership is a process that make use of influence. Which means it converges people's interest and demands well and also show people the right vision of national defense and make them to comply the policy about national security. Because of the environmental change, our national defense leadership is having a new turning point. First, international order, which is under post-cold war, raises possibility of guarantee of peace and security in international society but also, cause the increase of multiple uncertainty and small size troubles in security circumstance. In addition, Korean society is rushing into democratization and localization period by success in peaceful change of political power went through about three times. The issue of political neutralization of military is stepping into settlement but still, negative inheritance of old military regime is worrying about it. In this situation, we can't expect rise in estimation about the importance of security and military's reason for being. So, military have to give their concern to not only internal maintenance of order and control and growth of soldiers but also developing external leadership to strength influence to society and military's the reason for being. So for these alternative I'm suggesting a digital leadership of national defense which fits digital era. This digital leadership is the leadership which can accept and understand digital technology and lead the digital organization. To construct digital national defense we need a practical leadership. The leadership has to be digital leadership with digital competence that can direct vision of digital national defense and carry out the policy. A leader who ha s digital leadership can lead the digital society. The ultimate key to construct digital government, digital corporate and digital citizen depends on digital leader with digital mind. To be more specific, digital leadership has network leadership, next generation leadership, knowledge driven management leadership, innovation oriented leadership. A leader with this kind of leadership is the real person with digital leadership. From now on, to rise this, we have to build up human resource development strategy and develop educational training program.