• Korea Trade Review
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• v.42 no.5
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• pp.137-159
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• 2017

This study divides manufacturing in 18 countries including Korea, China, Japan and OECD countries into 11 areas and estimates and compares the technological efficiency of each industry. The traditional view of productivity is to increase production capacity through technological innovation or process innovation, but it is also influenced by the technological efficiency of production process. A Stochastic Frontier Production Model (SFM) is a representative method for estimating the technical efficiency of such production. First, as a result of estimating the production function by setting the output variable as total output or value-added, in both cases, the output increased significantly in all manufacturing sectors as inputs of labor, capital, and intermediate increased. On the other hand, R&D investment has a large impact on output in chemical, electronics, and machinery industries. Next, as a result of estimating the technological efficiency through the production function, when the total output is set as the output variable, the overall average of each sector is 0.8 or more, showing mostly high efficiency. However, when value-added was set, Japan had the highest level in most manufacturing sectors, while other countries were lower than the efficiency of the total output. Comparing the three countries of Korea, China and Japan, Japan showed the highest efficiency in most manufacturing sectors, and Korea was about half or one third of Japan and China was lower than Korea. However, in the food and electronics sectors, China is higher than Korea, indicating that China's production efficiency has greatly improved. As such, Korea is not able to narrow its gap with Japan relatively faster than China's rapid growth. Therefore, various policy supports are needed to promote technology development. In addition, in order to improve manufacturing productivity, it is necessary to shift to an economic structure that can raise technological efficiency as well as technology development.

• Analytical Science and Technology
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• v.22 no.4
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• pp.285-292
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• 2009

It has been observed that, after long term storage, some ammunitions are misfired by tamping (combustionstopping) due to aging of the chemicals loaded in the ammunitions. Used in ammunitions are percussion powder which provides the initial energy, igniter which ignites the percussion powder, and a delay system that delays the combustion for a period of time. The percussion powder is loaded first, followed by the igniter and then the delay system, and the ammunitions explode by the energy being transferred in the same order. Tamping occurs by combustion-stopping of the igniter or insufficient energy transfer from the igniter to the delay system or the combustion-stopping of the delay system, which are suspected to be caused by low purity of the components, inappropriate mixing ratio, size distribution of particulate components, type of the binder, blending method, hydrolysis by the humidity penetrated during the long term storage, and chemical changes of the components by high temperature. Goal of this study is to find the causes of the combustion-stopping of the igniter and the delay system of the ammunitions after long term storage. In this study, a method was developed for testing of the combustion-stopping, and the size distributions of the particulate components were analyzed with field-flow fractionation (FFF), and then the mechanism of chemical change during long term storage was investigated by thermal analysis (differential scanning calorimetry), XRD (X-ray diffractometry), and XPS (X-ray photoelectron spectroscopy). For the ignition system, M (metal)-O (oxygen) and M-OH peaks were observed at the oxygen's 1s position in the XPS spectrum. It was also found by XRD that $Fe_3O_4$ was produced. Thus it can be concluded that the combustion-stopping is caused by reduction in energy due to oxidation of the igniter.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.84-98
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• 2022

Estuary is important in terms of biodiversity because it has the characteristics of transition waters, created by the mixing of fresh- and seawater. The estuarine water circulation provides a variety of habitats with different environments by inducing gradients in the chemical and physical environment, such as water quality and river bed structure, which are ultimately the main factors influencing biological community composition. If the water circulation is interrupted, the loss of brackish areas and the interception of migration of biological communities will lead to changes in the spatial distribution of biodiversity. In this study, among the sites covered by the Estuary Aquatic Ecosystem Health Assessment, we selected study sites where changes in biodiversity can be assessed by spatial gradient from the upper reaches of the river to the lower estuarine area. The α-, γ- and β-diversity of diatom, benthic macroinvertebrates, and fish communities were calculated, and they were divided into open and closed estuary data and compared to determine the trends in biodiversity variation due to estuarine circulation. As results, all communities showed higher γ-diversity at open estuary sites. The benthic macroinvertebrate community showed a clear difference between open and closed estuaries in β-diversity, consequently the estuarine transects were considered as a factor that decreases spatial heterogeneity of their diversity among sites. The biodiversity trends analyzed in this study will be used to identify estuaries with low γ- and β-diversity by community, providing a useful resource for further mornitoring and management to maintain estuarine health.

• Journal of Navigation and Port Research
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• v.47 no.3
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• pp.147-154
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• 2023

This study aims to determine the necessity, role, utilization, and operation and management plan in relation to the underwater space platform where humans can newly reside. It provides a comprehensive opinion on the need for creating undersea space and operation plans based on opinions of industry-university-affiliated organizations involved in the R&D project of the Ministry of Maritime Affairs and Fisheries for the utilization of undersea space and external experts participating in marine technology development. In this study, a survey was conducted on researchers participating in the construction of a Korean submarine space platform. FGI was conducted on marine technology development experts. Results were then derived. As a result of the analysis, the need for subsea space construction was found to be high. As for the role of subsea space, the most common opinion was to develop technology for utilizing subsea space and to secure marine science research functions. It was found that the creation of subsea space would have a positive impact on the domestic industry, especially the deep-sea development industry and the shipbuilding/offshore structure industry. In terms of utilization, after the end of the seabed space test bed, the response to utilization as a marine observation base and marine ecosystem research had the highest proportion. As for expected inconvenience, discomfort in the psychological environment was the highest. Experts suggest that securing a continuous budget is most important for stable operation in the future and that securing a manpower budget is essential for itemized budgets. In addition, it was judged that it would be appropriate to establish a prior agreement from the time of the prior agreement and prepare a countermeasure before proceeding with the project in order to ensure ownership issues, consignment management issues, and cost issues when using the project after the end of the project.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.565-575
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast load is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, normal strength concrete structures require higher strength to improve their resistance against impact and blast loads. Therefore, a new material with high-energy absorption capacity and high resistance to damage is needed for blast resistance design. Recently, Ultra High Strength Concrete(UHSC) and Reactive Powder Concrete(RPC) have been actively developed to significantly improve concrete strength. UHSC and RPC, can improve concrete strength, reduce member size and weight, and improve workability. High strength concrete are used to improve earthquake resistance and increase height and bridge span. Also, UHSC and RPC, can be implemented for blast resistance design of infrastructure susceptible to terror or impact such as 9.11 terror attack. Therefore, in this study, the blast tests are performed to investigate the behavior of UHSC and RPC slabs under blast loading. Blast wave characteristics including incident and reflected pressures as well as maximum and residual displacements and strains in steel and concrete surface are measured. Also, blast damages and failure modes were recorded for each specimen. From these tests, UHSC and RPC have shown to better blast explosions resistance compare to normal strength concrete.

• 한국노년학
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• v.30 no.4
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• pp.1359-1375
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• 2010

Expecting the expansion of the elderly population under long-term home care with the coming of the aged society, this study purposed to propose a prevention and self-reliance support model and to get practical implications for minimizing dependency on care benefits and enhancing the effectiveness of prevention and self-reliance support. Research methods employed for this study were: first, reviewing theoretical literature for clarifying the concept of prevention and self-reliance support in providing long-term care benefits for the elderly; second, identifying factors hindering prevention and self-reliance support through analyzing standard long-term care use plans and documents related to long-term care benefits at elderly welfare centers to which the research subjects belonged; and third, surveying care benefit users on factors hindering their use of prevention and self-reliance support and their needs in the use of care benefits. Based on the results of the three types of qualitative research, we proposed directions for prevention and self-reliance support modeling and suggested practical implications for enhancing the effectiveness of prevention and self-reliance support. For this study, we collected documentary materials and conducted in-depth interviews with the participants with the consents and cooperation of managers and professional social workers at day care centers and elderly welfare centers in D City. According to the results of this study, literature review suggested that long-term care prevention and self-reliance support should be provided in a way of 'strengthening user-centered support systems,' which support elderly long-term care beneficiaries' right to lead a life as the subject of their own life. Document analysis found the absence of benefits related to health and medicine and lack of social support systems for prevention and self-reliance support, and the results of in-depth interviews suggested the necessity to strengthen services related to elderly long-term care beneficiaries' prevention and self-reliance, and the keen needs of the long-term care elders for prevention and self-reliance included: ① loneliness, anxiety, fear; ② missing for and worry about children and people; ③ moving, outing; ④ health and medical services, rehabilitation programs; ⑤ desire to use day care; ⑥ inconvenience of house structure; ⑦desire for meal menus; and ⑧ the occurrence of disuse syndrome. Based on these results, we suggested the base of prevention and self-reliance support modeling with three axes: ① strengthening user-centered support systems; ② strengthening support systems connected to health and medicine; and ③ strengthening social support systems.

• Korean Journal of School Psychology
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• v.9 no.3
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• pp.485-503
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• 2012

Academic engagement has been known as a strong predictor of students' cognitive and affective outcomes in an educational context. Despite increasing interest and theoretical usefulness of this construct, a few researchers seem to be interested in the validation of instruments to measure academic engagement for Korean students. Thus, this study would like to introduce one of academic scales widely used, UWES-S(Utrecht Work Engagement Scale-Student) (Schaufeli et al., 2002a: 2002b) and to validate the UWES-S for Korean college students. To validate the Korean version of the UWES-S, 651 college students (285 for Field Trial, 366 for Main Study) were used. The procedure is as follows. First, we used an integrated adaptation procedure to produce a Korean version of the UWES-S. Second, EFA(exploratory factor analyses) was applied to explore the factor structure of the UWES-S on the field trial data. Third, the psychometric properties of the UWES-S items were examined by graded response model(GRM). Also CFA(confirmatory factor analysis) was used to examine its internal construct validity for the data from the main study. Finally, the external validity of the UWES-S was scrutinized with the related variables such as academic motivation and satisfaction. As a result, the Korean version of the UWES-S with 13 items was accepted that the four items were excluded from its original version. Second, the internal validity was supported that the 3 factor CFA model(vigor, dedication, absorption) fit the data well. Third, we supported the partial mediation model that academic engagement played as a mediating variable between academic motivation(internal/external) and academic satisfaction. Finally, the differences between a validation of UWES-S for Korean college and high school students, the necessity of construct equivalence testing, and direction for future research of scale validating were discussed.

• Korean Journal of Social Welfare Studies
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• v.42 no.1
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• pp.333-370
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• 2011

This study views the aged inequalities according to the inequality hypothesis of the life course perspective in OECD 10 countries. Focusing on educational level which is early social status and welfare state regime which is social structure factors of inequality, this study analyzes income inequality for the aged who have transformed into old age period from non-aged period. The analysis is based on the data SHARE of Europe and HRS of USA. The main results of this study are summarized in four points. First, the income inequality is quite high by welfare system and the educational level. Second, the income inequality is somewhat reduced in case the people move from the period of non-aged to the period of aged. However, gini coefficient is still high(0.475). Considering welfare state regimes, although the income inequality is high in conservative regime of non-aged period, this would be higher in aged period. This result supports cumulative advantages/disadvantages hypothesis. The liberal regime remains high income inequality which supports the theoretical argument of status maintenance. Social democratic regime provides evidence to offer some support for the status leveling hypothesis. In there, income inequality is lower in aged period even though income inequality of non-aged period is low. Third, the cumulative advantages/disadvantages of disposable income according to educational level are strengthened and heterogeneity is grown in case people transition from the late period of non-aged to aged period. But public pension has been more equally distributed than gross income. Fourth, seeing welfare state regimes, public pension of aged-period is more inequally distributed than that of non-aged period in liberal and conservative regime. Specially in conservative regime, inequality of gross income is very high and public pension is also inequally distribute So this might show that the social security system strengthens the cumulative advantages/disadvantages. However, in the social democratic regime, public pension is more equally distributed than gross income and it could be much more equally distributed in aged period, which can support the status leveling hypothesis.

• Journal of the Korean earth science society
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• v.44 no.6
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• pp.655-674
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• 2023

This study examined whether the "self-guided interpretation" media in the Yeoncheon area of the Hantangang River UNESCO Geopark are intelligible for visitors. Accordingly, two on-site investigations were conducted in the Hantangang River Global Geopark in September and November 2022. The Yeoncheon area, known for its diverse geological features and the era of geological attraction formation, was selected for analysis. We analyzed the readability levels, graphic characteristics, and alignment with science curriculum of the interpretive media specific to geological sites among a total of 36 self-guided interpretive media in the Yeoncheon area. Results indicated that information boards, primarily offering guidance on geological attractions, were the most prevalent type of interpretive media in the Yeoncheon area. The quantity of text in explanatory media surpassed that of a 12^th-grade science textbook. The average vocabulary grade was similar to that of 11^th- and 12^th-grade science textbooks, with somewhat reduced readability due to a high occurrence of complex sentences. Predominant graphic types included illustrative photographs, aiding comprehension of the geological formation process through multi-structure graphics. Regarding scientific terms used in the interpretive media, 86.3% of the terms were within the "Solid Earth" section of the 2015 revised curriculum, with the majority being at the 4^th-grade level. The 11^th-grade optional curriculum terms comprised the second largest portion, and 13.7% of all science terms were from outside the curriculum. Notably, variations in the scientific terminology's complexity was based on geological attractions. Specifically, the terminology level on the homepage tended to be generally higher than that on information boards. Through these findings, specific factors impeding visitor comprehension of geological attractions in the Yeoncheon area, based on the interpretation medium, were identified. We suggest further research to effect improvements in self-guided interpretation media, fostering geological resource education for general visitors and anticipating advancements in geology education.

• Journal of Service Research and Studies
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• v.13 no.4
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• pp.131-141
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• 2023

Changes in consumer needs and behaviors according to lifestyle changes lead to consumption culture, affecting the automobile market. However, research and research to provide options tailored to the lifestyle of consumers in related markets are still insufficient. Focusing on pickup truck accessories applied to pickup trucks that reflect lifestyle the most among vehicle types, this study first examined the theoretical background of the aftermarket market and lifestyle of pickup trucks. Second, through image mapping, the market possibilities and opportunity factors of pickup trucks were discovered through market size analysis and possibilities, and through this, user types could be classified. Third, interviews were conducted with those representing user types, the contents were organized, and interviews were conducted centering on related groups to create a persona of a user group, and what needs each group's persona wanted. Finally, a design concept suitable for the issue keywords and insights derived for each user lifestyle type was presented. In this study, the user type was divided into ① outdoor activity type, ② hobby activity type, and ③ small-scale work type, and a design case study was conducted by applying the concept suitable for the keyword for each group. For the outdoor activity type, a variable storage structure and a living space-type accessory design were presented, and for the hobby type, a modular decktop design and a sports coupe-type hardtop design were presented. For the small business type, a partition that is easy to fix the load and a stepper design that is easy to board the cargo box were presented. It is expected that the size of the pickup truck aftermarket will be expanded by diversifying the option designs that users want by lifestyle by applying them to the development of pickup truck accessories that fit the lifestyle of pickup truck users in the automobile market, which is currently mass customized.