• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.217-223
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• 2010

In general, fiber-reinforced plastics (FRP) wastes are simply buried or burned. Landfill brings about a permanent contamination of soil due to the inability of FRP to decompose and incineration causes an issue of generating toxic gases and dusts. There have been several ways to treat the FRP wastes such as landfill, incineration, chemical recycling, material recycling and the utilization of energy from combustion. Most methods excluding material recycling are known to have critical limitations in economic, technical and environmental manners. However it is known that material recycling is most desirable among the methods handling FRP wastes. In this study, to investigate the purpose of feasibility of material recycling, various bulk molding compound (BMC) specimens were prepared with the various contents of unsaturated polyester resin binder (25, 30, 35 wt%) and the various replacement ratios of FRP wastes powder (0, 25, 50, 75, 100 wt%) substituted for filler. To evaluate the physical properties BMC specimens, various tests such as tensile strength, flexural strength, impact strength, hot water resistance and SEM imaging were conducted. As a results, mechanical strengths decreased with an increase of replacement ratio of FRP waste powder and physical properties of BMC specimens were deteriorated in the hot water resistance. The fluidity of BMC with more than 50 wt% of the replacement ratio of FRP wastes powder decreased remarkably, causing a problem in the BMC composite.

• Management & Information Systems Review
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• v.33 no.2
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• pp.101-118
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• 2014

In the mid-2000s, Web 2.0 appears and is becoming a general cultural code with the keyword of participation, sharing, and openness. Web 2.0, in which consumption is being transformed by the participatory web culture, has evolved. However, associated with the evolution of Web 2.0, several significant concerns appears in a society. Among them, this study will focuses on the cyber-ethics issues. There are limitations to solve the cyber-ethics problems only in the technical and legal approaches. Therefore, the current article intends to consider comprehensively the antecedents of cyber-ethics such as individual characteristics, social influence, and cultural characteristics. Specifically, (1) Do individual characteristics(i.e., self-efficacy, locus of control) affect cyber-ethics in the Web 2.0 environment?, (2) Do social influence(i.e., subjective norm) have an effect on cyber-ethics?, (3) Do cyber -ethics have an impact on user participation in the Web 2.0 services(i.e., retrieval and creation)?, finally (4) Do international cultural difference have a moderation effect on the relationship between cyber-ethics and user participation? For testing empirically the hypothesized research model, this study collected questionnaires in South Korea as well as U.S.A. The results showed that individual characteristics and social influence affect cyber-ethics toward user's creative activities in Web 2.0 sites.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.455-460
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• 2020

The governments of Korea, China, and Japan have operated comprehensive research institutes for railway technologies. Korea Railroad Research Institute (KRRI), China Academy of Railway Sciences Corporation Limited (CARS), and Railway Technical Research Institute (RTRI) are representatives of comprehensive railway research institutes in each country. KRRI was found to be the most advanced in the quantitative competitiveness of patents. In terms of qualitative competitiveness, KRRI has strength in civil engineering, whereas RTRI has strength in electricity. KRRI was found to have the greatest efforts in securing competitiveness in overseas property rights. By comparing the publication of papers, CARS published the most papers. On the other hand, from 2015, KRRI showed an upward trend and published the most papers. By examining the impact of the papers by the citation, KRRI was found to have higher competitiveness than the other two institutions. In the future, it will be necessary to perform big data analysis on patents and papers of the three organizations, derive the key research areas and promising technology areas for each institute, and establish a mid-to-long-term development plan for railway technology based on scientific evidence.

• Fire Science and Engineering
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• v.31 no.1
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• pp.26-35
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• 2017

Since the Northridge earthquake (1994) and Kobe earthquake (1995), the concept of performance-based design has been actively introduced to design major structures and buildings. Recently, the seismic design code was established for fire protection facilities. Therefore, the important fire protection facilities should be designed and constructed according to the seismic design code. Accordingly, uniform hazard spectra (UHS), with annual exceedance probabilities, corresponding to the performance level, such as operational, immediate occupancy, life safety, and collapse prevention, are required for performance-based design. Using the method of probabilistic seismic hazard analysis (PSHA), the uniform hazard spectra for 5 major cities in Korea with a recurrence period of 500, 1,000, and 2,500 years corresponding to frequencies of (0.5, 1.0, 2.0, 5.0, 10.0)Hz and PGA, were analyzed. The expert panel was comprised of 10 members in seismology and tectonics. The ground motion prediction equations and several seismo tectonic models suggested by 10 expert panel members in seismology and tectonics were used as the input data for uniform hazard spectrum analysis. According to sensitivity analysis, the parameter of spectral ground motion prediction equations has a greater impact on the seismic hazard than seismotectonic models. The resulting uniform hazard spectra showed maximum values of the seismic hazard at a frequency of 10Hz and also showed the shape characteristics, which are similar to previous studies and related technical guides for nuclear facilities.

• The Research Journal of the Costume Culture
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• v.4 no.3
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• pp.305-323
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• 1996

The purpose of this sty is to forecast the tendency of clothing colors, to provide materials useful for making the color plan for a better costume, and suggest new information in the apparel industry. To achieve these purposes, this study was carried out by suggesting vogue colors of recent apparel, along with the 20 standard colors of Muncell to 350 men and women in their 20s residing in Taegu.. We analysed and compared their preferred colors in suits vidual factor ;age, sex, education ,skin color, and body shape, and additionally classifying their interest in clothing colors, cause for color selection , degree of interest in color of clothes, color satisfaction of apparel market, and color combination of clothing, color satisfaction of apparel market, and color combination of clothing. We compared these elements according to their age, sex, and education. The results of this study is summarized as follows; 1. It was shown that both men and women in their 20s preferred warm colors the first colors mentioned being the most popular ; Pastels, Red, Blue and Black. They disliked dark and sordid colros in the order of Mauve, Khaki and Red. They preferred wearing Pastels and Yellow in the Spring, White, Blue, and Pastels were the favorites for summer, Beige in autumn, and black, Gray, and Beige in winter. The repugnated colors they chose two wear were Black, Red, Mauve, Khaki in spring and summer. Mauve, Red, Yellow were favorites for autumn, and Blue·White, Yellow·Green, and Pastels in winter. 2. The preferred colors for T-shirts were Yellow, Pastels, White in spring. White and Pastels were summer favorites, Beige an Red for autumn, and Black, Red, Beige in Winter. As for suits, the preferred colors in spring were in the order of Pastels, Beige and Yellow. The preferred colors of upper garments in summer were in the order of White and pastels. for lower summer garments Pastels, White and Blue were favorites. In autumn, Beige was shown to be highly preferred, and in winter, the order of preferred colors was Black, Gray and Beige. 3. On of those individual factors showing the greatest difference was sex. 4. Those factors having the greatest impact on the selection of clothing color were the season and their preference color. 5. The in vogue color of men in their 20s was at a higher level than hat of women. The groups that had an upper college level education showed a significant difference in their choices thant hose who were highschool graduates and technical college student and graduates. The consideration of inteterest in color of clothes, holding clothes during new purchasing, body shape and skin color was higher for women than men. In buying and wearing accessaries, women tend to take into consideration the harmony with the garment, and there was shown a significant difference between highschool graduates and the groups above the level of college education.

• Journal of the Korean earth science society
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• v.37 no.3
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• pp.162-172
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• 2016

Since the Northridge earthquake in 1994 and the Kobe earthquake in 1995 occurred, the concept of performance based design has been introduced for designing various kinds of important structures and buildings. Uniform hazard spectra (UHS), with annual exceedance probabilities, corresponding to the performance level of each structure, are required for performance-based design. The probabilistic seismic hazard analysis was performed using spectral ground motion prediction equations, which were developed from both Korean Peninsula and Central and Eastern US region, and several seismotectonic models suggested by 10 expert panel members in seismology and tectonics. The uniform hazard spectra for 5 highly populated cities in Korea, with recurrence period of 500, 1,000, and 2,500 years using the seismic hazard at the frequencies of 0.5, 1.0, 2.0, 5.0, 10.0 Hz and Peak ground acceleration (PGA) were analyzed using the probabilistic seismic hazard analysis. The sensitivity analysis suggests that spectral ground motion prediction equations impact much more on seismic hazard than what seismotectonic models do. The uniform hazard spectra commonly showed a maximum hazard at the frequency of 10 Hz and also showed the similar shape characteristics to the previous study and related technical guides to nuclear facilities.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.392-401
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• 2014

This research was carried out to understand the impact of mountainous torrent on topographical change of slope and sediment volume within a deposit line by dredging of soil erosion control dam. Terrestrial LiDAR surveys were conducted at dredged and non-dredged sites. Terrestrial LiDAR has an advantage on detecting topographical changes easily without demanding workmanship and technical skill for users. The distribution of erodible slope ($20^{\circ}-40^{\circ}$) was higher in non-dredged site than that of dredged site. However, the distribution was higher in dredged site than that of non-dredged site after rainy season. Erosion and deposition appeared regularly in a dredged site, but those occurred irregularly in the non-dredged site. The inflow of soil per square meter was 1.7 times higher in dredged site than that of non-dredged site after rainy season. The difference of rainfall in each site did not affect to soil erosion. The distribution of erodible slope was increased in dredged site than that of non-dredged site after rainy season due to inflow of soil from upper stream caused by dredging.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.423-428
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• 2016

The last stage blades of a low pressure (LP) turbine get frequently fractured because of stress corrosion cracking. This is because they operate in a severe corrosive environment that is caused by the impurities dissolved in condensed steam and high stress due to high speed rotation. To improve the reliability of the blades under severe conditions, 12% Cr martensitic stainless steel, having excellent corrosion resistance and higher strength, is widely used as the blade material. This paper shows the result of root cause analysis on a blade which got fractured suddenly during normal operation. Testing of mechanical properties and microstructure examination were performed on the fractured blade and on a blade in sound condition. The results of testing of mechanical properties of the fractured blade showed that the hardness were higher but impact energy were lower, and were not meeting the criteria as per the material certificate specification. This result showed that the fractured blade became embrittled. The branch-type crack was found to have propagated through the grain boundary and components of chloride and sulfur were detected on the fractured surface. Based on these results, the root cause of fracture was confirmed to be stress corrosion cracking.

• Journal of Technology Innovation
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• v.24 no.2
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• pp.57-89
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• 2016

This paper used individual establishment level data to estimate the effects of government support for the research and development of 'small and medium enterprises'(SMEs). We analyzed, on the establishment level, the degree of technical advancement, strength of private R&D incentives, and the effect on employment levels of firms which participated in the 2010 government R&D support project. The results of this study are as follows. First, the size and frequency of government investment in the R&D of SMEs were both positively correlated with the amount of patent registrations. Furthermore, we found that the amount of patent registrations were positively correlated with the size of the establishments, but the average level of technological advancement for the firms running the research was lower than the average level of technological advancement for the firms merely participating in the project. Second, the government's R&D policy was found to be complementary to private R&D incentives, and a 1% increase in government R&D investment resulted in an inelastic increase (0.193~0.245%) of the firms' post-program R&D spending. Third, we found that R&D support from the government contributed to an increase of employment by the participating firms. Additionally, we found that the impact of R&D support on job creation varied for the firm size and technological characteristics. Therefore, it is important for governments to take into consideration each type of small business, when setting R&D policies.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.257-262
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• 2019

Lattice steel towers for overhead transmission lines have been replaced by tubular steel poles due to the visual impact of large and complex shape of truss type. Demand for tubular steel poles consisting of a single frame member continues to grow because of its advantages such as visual minimization, architectural appeal and minimal site consumptions. However, there are some constraints on the transportation and construction. As the diameter of tower base has been enlarged, it may exceed minimum height limit required to pass the tunnel in case of land transportation. Also, in a narrow place where it is not easy to secure the installation areas such as mountainous places, there might be some areas wherein it must secure a wide working space so that large vehicles and working cranes will be allowed to enter. In this paper, we presented a vertical separated tubular steel pole, which is a new type of support that can be implemented for general purpose such as mountainous areas or narrow areas to improve the issues raised by breaking away from the conventional design and fabrication methods. Technical approaches for overcoming the limit of the cross-sectional size is to separate and modularize the cross-section of the tubular steel pole designed with a size that cannot be carried or assembled, and to lighten it with a weight capable of being transported and assembled in a narrow space or mountainous area. As a result of this research, it will be possible to enter small and medium sized vehicles in locations where it is restricted to transport by large-sized vehicles. In the case of mountainous areas, it will be possible to divide it into a weight capable of being carried by a helicopter and it will be easy to adjust and fabricate it with individual modules. Furthermore, in order to break away from the traditional construction method, we proposed the equipment that can be applied to the assembly of Tubular Steel Pole without using a large crane in locations where there is no accessible road or in locations wherein large cranes cannot enter. In particular, this paper shows the movable assembling equipment and some methods that are specialized for vertical separated tubular steel pole consisting of members with reduced weight. The proposed assembly equipment is a device for assembling the body of the Tubular Steel Poles. It will be installed inside the support and the modules can be lifted by using the support itself.