• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.456-464
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• 2016

Increasing the strength of structural materials allows their self-weight to be reduced and this, in turn, enables the structures to satisfy esthetic requirements. The yield strength of high-performance steel is almost 480 MPa, which is approximately 50% higher than that of general structural steel. The use of high strength materials, however, makes the sections more slender, which can potentially result in significant local stability problems. The strength of slender element sections might be governed by their elastic buckling behavior, and the elastic buckling strength is very sensitive to the boundary conditions. Because the web provides the boundary conditions of the compressive thin-flange, the stiffness of the web can affect the elastic buckling strength of the flange. In this study, therefore, the effects of the flange and web slenderness ratios on the elastic flange local buckling of I-girders subjected to a pure bending moment were evaluated by finite element analysis (FEA). The analysis results show that the elastic local buckling strength and buckling modes were affected not only by the web support conditions, but also by the flange and web slenderness ratios.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.72-80
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• 2015

In this study, comparative analysis has been performed with regard to a bending stress and deformation at bottom slab of a concrete floating container terminal by live load distributions. In addition, a structural performance and behavior of the floating structure is considered using a numerical analysis. Through reviewed structural performance of a floating structure by live load distribution, the structure presented tensile behavior by two live load cases (A, B, D-type). Then, the other live load cases (C, E, F, G, H, I, J-type) shows compressive behavior. Especially, immoderately compressive stress was generated on bottom slab at specific load distribution. but, that should be decreased through controling buoyancy pre-flexion. Through reviewed structural behavior, slopes of structure by four live load cases (B, E, F, H-type) were exceeded in design criteria of mega-float. It should be estimated that it get out of the load case at loading container. In all, the present study can be considered as a benchmark of a floating container terminal in the absence of analysis and will be used to guide-line about serviceability of concrete floating container terminal.

• Journal of Korean Foot and Ankle Society
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• v.20 no.3
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• pp.112-115
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• 2016

Purpose: We aimed to investigate the safety zone for Achilles tendon insertion in the posterior aspect of the calcaneus via the use of magnetic resonance imaging (MRI) when planning for insertional Achilles tendinopathy. Materials and Methods: This study included 95 patients. The MRI of midsagittal plane of the ankle joint was used to measure the proximal and distal insertion point for the Achilles tendon in the posterior aspect of the calcaneus. Patients were divided into three groups according to the proportion of the distal insertion point out of the entire calcaneal length: the proximal, middle, and distal insertion groups. Results: The mean proximal and distal insertion points for the Achilles tendon were measured as 1.05 cm (0~2.11 cm) and 2.36 cm (1.60~2.93 cm), respectively. When the posterior aspect of the calcaneus was used as the reference plane, none of the patients was in the proximal insertion group, while 75 and 20 patients were in the middle and distal insertion groups, respectively. The insertion portion was longer in the distal insertion group ($1.47{\pm}0.25cm$) than in the middle insertion group ($1.27{\pm}0.35cm$). Statistically significant differences with respect to the length of the insertion portion were observed between the two groups (p=0.008). Conclusion: Removal of more than 1 cm below the superior margin of the posterior calcaneus may be dangerous. An MRI study on the Achilles tendon of patients without hindfoot deformity or tendinopathy revealed various insertional characteristics. Preoperative MRI evaluation is safer than relying solely on the simple radiological assessment when planning for insertional Achilles tendinopathy.

• Explosives and Blasting
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• v.22 no.3
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• pp.57-64
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• 2004

There are two major types of underwater blasting at Korea, bridges and harbor construction work. Pier blasting for lay the foundation bridges construction is used dry excavation working (drilling and charging) after pump out water and then fire pump in water that is same as bench blasting. In contrast, underwater blasting for harbor construction and increase of harbor load depth is used to barge with digging equipment that is in oder to drilling on the surface and blasting work(charge, hook-up) under water. Thus, there are need to special concern such as charge method and hook-up method different from tunnel blasting work and bench blasting work. If do not use special concern breaks out dead pressure and mis fire because of there are so many difficult condition such as water pressure, obstruct field of vision. In this study underwater blasting at Busan Harbor Construction have consider with special concern that is plastic pipe charge method used to MegaMITE I and specialized buoy hook- up method make far initial system detonate on the surface used to TLD. The results is designed blast pattern charge per delay effect an inspection of verify between predict velocity and measure velocity. minimized break out mis fire consideration charge method, hook up method. According to result best underwater blasting design is 105mm drilling dia, MeGAMITE II, HiNLL Plus(non electric detonator).

• Journal of the Korean association of regional geographers
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• v.19 no.3
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• pp.454-475
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• 2013

In 2011, Daegu hosted the International Association of Athletics Federation Championships and attempted to use this event strengthen its global profile. Organizers hoped Daegu 2011 would strengthen knowledge about Daegu internationally and help the city overcome recent economic stagnation by bolstering tourism and investment on the global scale. Written from the perspective of a foreigner living in Korea, this interpretive article uses mixed-method cultural geographic analysis to evaluate the momentum Daegu 2011 produced in these directions. The article draws on a tripartite "territorialisation" approach to mega-event tourism's production of space, focusing on representational efforts during the approach to the championships and the event itself. Promotional materials receive particular attention. Interviews with international tourists during 2011 strengthen conclusions drawn from analysis of promotional materials. After reviewing relevant conceptual literature, Daegu's history, and the background of Daegu 2011, the article devotes three subsections to analysis. The first uses critical discourse analysis of a key promotional video to argue that Daegu's self-promotions betrayed insecurity about the city's place within the global tourism market. A second analysis subbsection finds that additional promotional materials did not fully overcome that problem. These materials also produced an overload of Daegu images and aspirations. The third subsection further develops these arguments, pointing to a partial mismatch between images emphasized by promotions and experiences available in the tourism landscape. This subsection also argues that while Daegu 2011 undoubtedly produced positive effects for the city, key challenges remain if Daegu will be placed on the map of globally acknowledged cities.

• Journal of Life Science
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• v.30 no.7
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• pp.625-629
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• 2020

The Ocean is a rich source of diverse living organisms include viruses. In this study, we examined the microbial communities in the sea adjacent to Jeju Island in two seasons by metatranscriptomics. We collected and extracted total RNA, and, using the next-generation sequencing HiSeq 2000 and de novo transcriptome assembly, we identified 652,984 and 163,759 transcripts from the March and December samples, respectively. The most abundant organisms in March were bacteria, while eukaryotes were dominant in the December sample. The bacterial communities differed between the two samples, suggesting seasonal change. To identify the viruses, we searched the transcripts against a viral reference database using MegaBLAST with the most identified being bacteriophages infecting the marine bacteria. However, we also revealed an abundance of transcripts associated with diverse herpesviruses in the two transcriptomes, indicating the presence or possible threat of infection of fish in the sea around Jeju Island. This data is valuable for the study of marine microbial communities and for identifying possible viral pathogens.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.1
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• pp.1-17
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• 2020

The study aims to identify economic interdependencies between regions and define functional economic areas of Korea by analyzing inter-firm transaction networks. Previous research has relied on pre-given administrative boundaries or cultural homogeneity and used data such as commuting, population movement, and cargo flows which could not fully explain economic activities. To overcome the limitations, this study applies a community detection method to inter-firm transaction networks derived from the CRETOP+ database of Korean corporate data. The novel dataset and the network analysis enables us to identify Korea's functional economic areas based on actual inter-firm linkages. The result shows that there are six to seven economic blocs in the networks as of 2018. In particular, one huge economic bloc is formed integrating the Seoul metropolitan area, Chungcheong, and Gangwon provinces. Meanwhile, North Jeolla and South Jeolla provinces form two economic blocs separately rather than being tied up in one bloc due to the low frequency of transactions between each other. The two big economic blocs of Daegu-Gyeongbuk and Busan-Gyeongnam exist, and interestingly, Ulsan, Gyeongju, and Pohang form a separate middle-sized bloc across the administrative boundaries. The results reveal that the future balanced national development policies should be implemented based on functional economic areas derived from empirical data.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.293-302
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• 2010

Taxa of Artemisia collected in Korea were constructed by molecular phylogenetic analysis based on the internal transcribed spacer(ITS) regions of nrDNA. The length of the ITS sequences aligned using the clustal X program was 636~643 bp, and the lengths of the ITS1 and ITS2 regions were 251~255 bp and 217~222 bp, respectively. The total number of variable sites was 95 for the entire sequence, and a parsimony- informative site represented an efficacious site in ITS1 rather than in ITS2. The maximum parsimony tree as calculated by the MEGA 4 program was clustered into five clades. The taxa(A. capillaris, A. japonica var. japonica, A. japonica var. hallaisanensis, A. japonica subsp. littoricora) degenerated ovary of clade 1 was supported as the subgenus Dracunculus by Ling's classification system. The results show that A. nakaii and A. fukudo were quite similar genetically(Boostrap 99%) and that the scientific name of Korean A. dubia should be reconsidered. A. sp. distributed in Ganghwa province was grouped with A. argyi(Boostrap 89%). These results suggest that the molecular techniques used in this study could be useful for the phylogenetic analysis of Korean Artemisia herbs having variations in their morphological characteristics.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.290-295
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• 2013

The purpose of this study was to investigate the shear bond strength between various commercial all-ceramic system core and veneering ceramics, and evaluate the clinical stability by comparing the conventional metal ceramic system. The test samples were divided into three groups: Ni-Cr alloy (metal bond), yttria-stabilized, tetragonal zirconia polycrystal (Y-TZP) (zirconia bond), lithium disilicate (lithium disilicate bond). The veneering porcelain recommended by the manufacturer for each type of material was fired to the core. After firing, the specimens were subjected to shear force in a universal testing machine. Load was applied at a crosshead speed of 0.50 mm/min until failure. Average shear strengths (mega pascal) were analyzed with a one-way analysis of variance and the Tukey test (${\alpha}$=0.05). The mean shear bond strength${\pm}$SD in MPa was $44.79{\pm}2.31$ in the Ni-Cr alloy group, $28.32{\pm}4.41$ in the Y-TZP group, $15.91{\pm}1.39$ in the Lithium disilicate group. The ANOVA showed a significant difference among groups (p<0.05). None of the all-ceramic system core and veneering ceramics could attain the high bond strength values of the metal ceramic combination.

• Plant Journal
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• v.11 no.1
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• pp.39-49
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• 2015

The objective of this study is to improve the classification structure of commodity code for piping material management which is considered as the fundamental of commodity code and piping material management system. It enhances the efficiency of piping material management directly or indirectly affecting the engineering, procurement and construction in a petrochemical plant projects. To establish an improved code classification structure, this study identifies the problems of former code classification structure in details, as well as the characteristics of other domestic and global EPC company's code classification structures and presents the improved direction considering the recently mega-sized and specialized projects. Accordingly, to efficiently enhance piping material management, the improved code classification structures have been derived from defining suitable code classification structure for specific piping component, adding more standard attribute, expanding the number of code digits and classifying code hierarchy. The results of applying the improved classification structure of commodity code to on-going project have led to reduce the rate of rework from 4.98% to 2.48% for developing purchase description and also have saved working time for executing piping design by 3D modeling from 6 months by two persons to 4 months by a person which is decreased 67% consequently. In addition, the structures of pyramid code management have resulted to accumulation and analysis of the various piping data for other disciplines such as procurement and estimation team which require commodity code information through the company's material control system.