• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.21-29
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• 2020

This study analyzed problems of operating performance bond for public works and derived some suggestions for improvement. The Contract Law for Government Owner requires to submit performance bond which guarantees performing the construction contractor pays back compensation money when the obligation is not executed. Currently, first bid eligibility for participation is exactly required for executing company of performance bond obligation, not considering volume, technical level, and special type of remaining works. In collaboration contract, if guarantee accident occurs, it is obliged for remaining collaboration contractors to be qualified to fulfill the whole contract. This study proposes following improvement plan to solve problems of current performance bone in public works. Firstly, qualification criteria must be deregulated exceptionally for selecting proper contractor, which executing performance bond obligation, considering progress and characteristics of remaining works. Secondly, In collaboration contract, the prerequisite of remaining contractors' should be deregulated as 'implementation requirement of the remaining works'from'implementation requirement of the whole work'. Finally, defect responsibility should be included in liabilities of performance bond by specifying that owner or guarantee agency bear them.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.217-221
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• 2015

When reactor coolant leaks occur due to cracks of a steam generator's tube, radioactive materials contained in the primary cooling water in nuclear power plant are forced out toward the secondary systems. At this time the secondary water purification resin in the ion exchange resin tower of the steam generator blowdown system is contaminated by the radioactivity of the leaked radioactive materials, so we pack this in special containers and store temporarily because we could not dispose it by ourselves. If steam generator tube leakage occurs, it produces contaminated spent resins annually about 5,000~7,000 liters. This may increase the amount of nuclear waste productions, a disposal working cost and a unit price of generating electricity in the plant. For this reasons, it is required to develop a decontamination process technique for reducing the radioactive level of these resins enough to handle by the self-disposal method. In this research, First, Investigated the structure and properties of the ion exchange resin used in a steam generator blowdown system. Second, Checked for a occurrence status of contaminated spent resin and a disposal technology. Third, identified the chemical characteristics of the waste radionuclides of the spent resin, and examined ionic bonding and separation mechanism of radioactive nuclear species and a spent resin. Finally, we carried out the decontamination experiment using chemicals, ultrasound, microbubbles, supercritical carbon dioxide to process these spent resin. In the case of the spent resin decontamination method using chemicals, the higher the concentration of the drug decontamination efficiency was higher. In the ultrasound method, foreign matter of the spent resin was removed and was found that the level of radioactivity is below of the MDA. In the microbubbles method, we found that the concentration of the radioactivity decreased after the experiment, so it can be used to the decontamination process of the spent resin. In supercritical carbon dioxide method, we found that it also had a high decontamination efficiency. According to the results of these experiments, almost all decontamination method had a high efficiency, but considering the amounts of the secondary waste productions and work environment of the nuclear power plant, we judged the ultrasound and supercritical carbon dioxide method are suitable for application to the plant and we established the plant applicable decontamination process system on the basis of these two methods.

• Economic and Environmental Geology
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• v.52 no.5
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• pp.459-469
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• 2019

We present a quantitative evaluation of density, vesicularity and microtextures for coarse lapilli collected from the Jugam Scoria Deposits, northeastern Ulleung Island. Lapilli from the deposits have modal vesicularities of 61% in the lower part and 67% in the upper part, and vesicle populations dominated by non-interconnected subround vesicles. Clasts of modal vesicularity have margin-parallel zonation, with subaerially quenched rims interpreted to preserve "syn-fragmentation" magmatic textures in microlite-free sideromelane rims, grading "post-fragmentation" tachylitic interiors with vesicle and microlite textures that progressively coarsen from rim to interior. Degassing scenarios are linked to syn-fragmentation vesicle textures to demonstrate that the magmas degassed in dominantly closed systems. And diffusion-controlled cooling rates of trachyandesitic pyroclasts in contact with atmosphere are linked to post-fragmentation evolution of vesicle and microlite textures to infer about transportation and dispersal of the pyroclasts in low shooting jets. These textural analyses show that the Jugam eruptions were strictly applied to the strombolian type, analogous to the hawaiian type among any classical subaerial eruption type.

• Korean Journal of Remote Sensing
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• v.35 no.5_2
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• pp.763-772
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• 2019

High-resolution satellites capable of observing the Earth periodically enhance applicability of remote sensing in the field of national disaster management from national disaster pre-monitoring to rapid recovery planning. The National Disaster Management Research Institute (NDMI) has been developed various satellite-based disaster management technologies and applied to disaster site operations related to typhoons and storms, droughts, heavy snowfall, ground displacement, heat wave, and heavy rainfall. Although the limitation of timely imaging of satellite is a challenging issue in emergent disaster situation, it can be solved through international cooperation to cope with global disasters led by domestic and international space development agencies and disaster organizations. This article of special issue deals with the scientific disaster management technologies using remote sensing and advanced equipments of NDMI in order to detect and monitor national disasters occurred by global abnormal climate change around the Korean Peninsula: satellite-based disaster monitoring technologies which can detect and monitor disaster in early stage and advanced investigation equipments which can collect high-quality geo-information data at disaster site.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.3
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• pp.291-303
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• 2019

This study analyzed the changes in the industrial environment surrounding the Gumi region and the status of the industrial crisis in the Gumi area amid such changes. The Gumi region is experiencing a more turbulent period than ever in the environment changes at the international, national and local levels, such as the transition to the Fourth Industrial Revolution, the weakening of the competitiveness of key industries including mobile devices and displays, and the moving-out of core companies such as Samsung and LG Group. Accordingly, efforts have been made to diversify the industrial structure by fostering industry of automobile parts, high-tech medical devices and carbon materials to cope with and adapt to environmental changes at the regional level. However, the Gumi region is still locked in to the mono-cultural, large enterprise-dependent industrial structure centering on the mobile and display sectors, failing to overcome the regional industrial crisis and stagnating the overall local economy. The relocation of large companies began to increase in the 2010s, reducing the protection of large corporations against environmental changes at the corporate level. As a result, the crisis factors of small and mediumsized enterprises are gradually expanding to the national and international scale and working more complexly, which is beyond the level they can afford. So it is highly likely that the current industrial crisis will deepen. Therefore, it is necessary to strengthen the resilience to adapt to changes in the environment when it comes to overcoming the industrial crisis in Gumi region. To this end, it is necessary to improve innovation capabilities and diversify businesses based on convergence and complex technologies at the enterprise level, and to be selected as a special crisis response area aimed at creating an innovative ecosystem through autonomous resonance of companies and industries at the local level.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.652-660
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• 2017

Recently, the number of tourists using cruise ships in Korea is increasing. and an big cruise ship with an gross tonnage of 160,000 tons or more has entered the domestic ports. Therefore, the government has been making a lot of efforts to confirm the cruise infrastructure for revitalization of the domestic cruise industry. However, there are no standards for cruise ship specifications and water facilities in the domestic port and fishery design standards. Currently, construction of dedicated cruise facilities is under way in major domestic ports. However, due to lack of specifications and domestic standards for cruise ships, it is difficult to design and license special facilities. Therefore, in this study, PIANC rule and domestic harbor and designing standard of fishing port were compared and analyzed in order to present the standard specification of cruise ships. And analyzed the representative linearity of cruises currently being operated. As a result of the ship characteristics analysis, There was a difference in coastal passenger ship in specifications and ship maneuverability. Therefore, in order to design facilities dedicated to cruising, the specifications of the target ship must be included in the domestic design standard. In addition, in order to calculate the scope of the target ship, I applied the coverage rate of 75% to the average specification value of the cruise ship and presented the standards of the cruise ship and the standard of the water area facilities.

• Journal of the Korean Magnetics Society
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• v.26 no.1
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• pp.1-6
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• 2016

Pd has the highest magnetic susceptibility among single element metals and often shows ferromagnetism under some special environments. In this paper, we report magnetism of 5- and 9-monolayers (ML) calculated by using full-potential linearized augmented plane wave method. Exchange-correlation interaction is taken into account in local density approximation (LDA) and generalized gradient approximation (GGA) and calculational results in LDA and GGA are compared with each other. It is found that calculations by LDA are more reliable compared to those by GGA because LDA prediction of paramagnetism of bulk Pd is consistent with experiments, whereas GGA predicts wrongly ferromagnetim of bulk Pd. Calculational results in LDA on a 5-ML Pd(111) thin film shows a ferromagnetic ground state unlike a paramagnetic ground state of bulk Pd. The center Pd layer of the 5-ML Pd(111) thin film has the largest magnetic moment ($0.273{\mu}_B$) among the layers and |m| = 1 orbital states play a dominant role in stabilizing the ferromagnetism of the 5-ML Pd(111) thin film. A 9-ML Pd(111) thin film in a ferromagnetic state has almost the same total energy as in a paramagnetic state. Since the magnetization of the 9-ML Pd(111) thin film is stable, the ferromagnetic state may be meta-stable.

• Food Science and Preservation
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• v.14 no.2
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• pp.160-164
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• 2007

This study was performed to investigate the effects of mixing methods, storage period, and dilution ratio of Dangyuja-sugar mixture on the customer preferences for Dangyuja-tea. Most sensory characteristics such as bitterness, flavor, and taste are influenced more by mixing methods of Dangyuja-sugar mixtiue than by storage period. The Dangyuja-sugar mixture prepared by slice cutting is preferred to those prepared by operating electric mixer, The preference test showed that the appearance is not influenced by storage period but by mixing methods, whereas the tne and texture is more affected by storage period in which the 24 month storage is preferred to 12 month storage. therefore, the overall preference fer Dangyuja-tea is the on that prepared with 20% contents of Dangyuja-sugar mixture which is slice-cut and 24 month stored.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.197-205
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• 2010

This study was carried out to investigate the flora and vegetation in wetland of Mueuido. The forest vegetation was classified into 2 communities group (Utricularia bifida-Eriocaulon sikokianum and Alnus japonica) and 6 communities (Rhynchospora chinensis, Phragmites communis, Molinia japonica, Ischaemum crassipes, Quercus serrata and Pinus rigida-Miscanthus sinesis). Resources vascular plants were composed of 30 families, 53 genera, 50 species and 8 varieties, totaling 58 taxa. Among the investigated resources plants, Utricularia bifida and Utricularia racemosa were rare and endangered species. The special plants based on floral region by Ministry of Environment were 5 taxa; V rank species 2 taxa, II rank species 1 taxa and I rank species 2 taxa. A naturalized plants was 1 species of totaling 290 species appeared in South Korea. The Life-form were Hydatophytes (20.7%), Geophyte (19%), Microphanerophytes (19%), Hemicryptophytes (17.2%), Nanophanerophytes (17.2%), Chamaephytes (5.2%), Therophytes (1.7%). In marsh-type wetland of Mueuido, we predict that bog-type swamp, where various type of swamp plants are distributed, is starting to be formed based on the fact that Utricularia bifida and Utricularia racemosa, insectivorous plants, are dominant and sphagnum also is found. Along with the notion, there are reportedly found serious damages around wetland by human being and we have to prepare protection plans against it.

• Journal of the Korean Society of School Health
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• v.18 no.1
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• pp.47-58
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• 2005

Purpose:　This study is a descriptive correlation survey with the purpose of identifying the relationship between family function and hope in adolescents. It was done to provide basic data for developing family centered nursing strategies to promote adolescents' hope. Methods: The subjects of this study were 1030 high school students in J city. Data were analyzed with SPSS 10.0 program. Frequencies and percentages were used to compare the subjects' general characteristics. Minimum values, maximum values, mean scores and mean grades were used to identify the level of family function and hope. Pearson's correlation coefficient was used to analyze the relationship between family function and hope in adolescents, and t-test, ANOVA, and Scheffe test were used to examine the level of family function and hope by general characteristics. Results:　1. The level of adolescents' family function ranged from 26 to 97, the mean score was 66.85$\pm$13.16, and the mean grade was 2.76$\pm$0.52. 2. The level of adolescents' hope ranged from 55 to 153, the mean score was 111.48$\pm$17.64 and the mean grade was 2.78$\pm$0.44.　3. It showed that there is a significantly positive correlation (r=0.546, p=.000) between adolescents' family function and hope. That is, the better family function adolescents have, the higher level of hope they have. 4. Adolescents' family function showed significant differences according to school record (F=6.363, p=.002), school life satisfaction (F=4.922, p=.007), father's education (F=2.640, p=.048), mother's education (F=3.586, p=.013) and domestic economy status(F=3.022, p=.049).　5. Adolescents' hope showed significant differences according to religion (t=2.018, p=.044), school type (t=2.567, p=.010), school record (F=9.712, p=.000), school life satisfaction (F=11.367, p=.000), father's education (F=4.632, p=.003), mother's education (F=4.709, p=.003), domestic economy status (F=4.235, p=.015), relationship with friends (F=8.187, p=.000), and subjective health condition (F=5.490, p=.001). Conclusion: First, in order to improve adolescents' family function, which encourages hope in adolescents, it is necessary to develop nursing interventions and to make further studies.　Second, it is necessary to develop instruments for improving Korean adolescents' family function and hope. Third, further studies are required to improve adolescents' family function and hope in special situations such as disease, drug abuse and juvenile delinquent.