• Tunnel and Underground Space
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• v.22 no.6
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• pp.412-428
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• 2012

To achieve mine development, a large amount of data concerned with the geological structure and the ore body had to be investigated and collected through geological survey, drilling and geophysical explorations. In most previous cases, however, the data were usually analyzed two dimensionally and those results showed some limits because of their 2D presentation. Those 2D maps such as geological plane sections or longitudinal sections cause lots of difficulties in understanding the complex geological structure or the feature of ore body in a spatial way. In this study, research area was set on the abandoned Yangyang iron mine in Korea and the Sugaeng ore body within the mine was selected as the research target to design a mine haulage system for reopening. A 3D mine model of this area was tried to be constructed using a 3D modelling software, GEMS. An accurate 3D model including the ore body, the geological structure, the old underground mine drifts and the new mine drifts was constructed under the purpose of reopening of the abandoned iron mine. Especially, mine design for trackless haulage system was conducted. New inclines and drifts were planned and modelled 3 dimensionally considering the utilization of old drifts and shaft. In addition to the 3D modelling, geostatistical technique was adopted to generate a spatial distribution of the ore grade and the rock physical properties. 3D model would be able to contribute in solving problems such as evaluating ore reserves, planning the mine development and additional explorations and changing the development plans, etc.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.54-63
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• 2015

This study was conducted to investigate the flora and vegetation structure at a 15-year-old artificial wetland for the water purification in Jincheon, Korea. The percentage of species number of obligate wetland plants and facultative wetland plants totaled 40%, whereas that of obligate upland plants and facultative upland plants was 57%. This result showed that the artificial wetland in the study experienced terrestrialization. The number of annual and biennial plants that are pioneer vegetation in a successional stage was lower than that of perennial herbs as a result of the long-term stabilization of vegetation. From the results of DCA (detrended correspondence analysis), water depth played an important role on the classification of vegetation structure in an old artificial wetland. Species diversity was higher in the terrestrialized plant communities such as Iris pseudacorus and Aster koraiensis than in any other wetland communities. Plant communities could be classified according to the wetland indices; obligate upland for A. koraiensis community, facultative wetlands for Carex dispalata var. dispalata and I. pseudacorus community, and obligate wetlands for Nymphoides peltata, Nymphaea tetragona, Phragmites communis, Potamogeton maackianus, and Typha angustifolia community. In conclusion, this result suggests that wetland vegetation should be maintained against terrestrialization through the proper management of sedimentation and hydrological regime in an artificial wetland.

• Restorative Dentistry and Endodontics
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• v.34 no.1
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• pp.69-79
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• 2009

The purpose of this study was to evaluate the influence of elastic modulus of restorative materials and the number of interfaces of post and core systems on the stress distribution of three differently restored endodontically treated maxillary second premolars using 3D FE analysis. Model 1, 2 was restored with a stainless steel or glass fiber post and direct composite resin. A PFG or a sintered alumina crown was considered. Model 3 was restored by EndoCrown. An oblique 500 N was applied on the buccal (Load A) and palatal (Load B) cusp. The von Mises stresses in the coronal and root structure of each model were analyzed using ANSYS. The elastic modulus of the definitive restorations rather than the type of post and core system was the primary factor that influenced the stress distribution of endodontically treated maxillary premolars. The stress concentration at the coronal structure could be lowered through the use of definitive restoration of high elastic modulus. The stress concentration at the root structure could be lowered through the use of definitive restoration of low elastic modulus.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.619-627
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• 2013

Deutzia paniculata Nakai is a Korean endemic species that has a very restricted distribution in Gyeongsang-do, South Korea. The genetic diversity and structure of five populations of D. paniculata were investigated using 31 ISSR loci from six primers. The Shannon's index (0.429) and genetic diversity (0.271) were relatively higher than those of other rare plant species in Korea. The Miryang (MY) and Yangsan (YS) populations, which have higher flowering rates than the other populations, showed greater genetic diversity than the other populations. An analysis of the molecular variance (AMOVA) showed that 16% of the total variation could be attributed to differences among the populations, and 84% to the differences within populations, indicating moderate gene flow among adjacent populations. The high genetic diversity and low genetic differentiation in the Deutzia paniculata populations, which have a restricted distribution, is considered to be affected by outcrossing of the mating system and abundant individuals in the populations. These results suggest that ex situ conservation strategies are needed to sustain the current genetic diversity of D. paniculata.

• Journal of the Korean Geotechnical Society
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• v.34 no.1
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• pp.5-16
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• 2018

In this study, seismic performance of geotechnical seismic isolation system capable of primary seismic isolation in the ground was evaluated. 1-G shaking table test was used to assess the performance of Teflon or steel slag as geotechnical seismic isolation systems installed beneath superstructure foundation. Response acceleration and response spectra were analyzed considering different input motions. The results were compared with those of fixed foundation structure without seismic isolation system. The steel slag-type seismic isolation system showed significant reduction in acceleration. The teflon-type seismic isolation system did not show significant effects on acceleration reduction in low-to-moderate seismicity condition, but it did show better effects in case of strong seismic condition. As input motion was transferred to the upper mass, the response spectrum of the fixed foundation structure was amplified in the short period range. In contrast, the response spectrum of the structure with seismic isolation using teflon or steel slag amplified in the long period range. It is found that the change of periodicity and the friction characteristics between isolation materials and foundations affected acceleration reduction.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.143-159
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• 2017

A probabilistic fragility assessment procedure is developed in this paper to predict risks of damage arising from seismic loading to the two-cell RC box tunnel. Especially, the paper focuses on establishing a simplified methodology to derive fragility curves which are an indispensable ingredient of seismic fragility assessment. In consideration of soil-structure interaction (SSI) effect, the ground response acceleration method for buried structure (GRAMBS) is used in the proposed approach to estimate the dynamic response behavior of the structures. In addition, the damage states of tunnels are identified by conducting the pushover analyses and Latin Hypercube sampling (LHS) technique is employed to consider the uncertainties associated with design variables. To illustrate the concepts described, a numerical analysis is conducted and fragility curves are developed for a large set of artificially generated ground motions satisfying a design spectrum. The seismic fragility curves are represented by two-parameter lognormal distribution function and its two parameters, namely the median and log-standard deviation, are estimated using the maximum likelihood estimates (MLE) method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.141-149
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• 2018

The structure of the coacervate can dramatically influence deposition on the hair. The purpose of this study was to investigate the effect of coacervate with a relatively fine and uniform structure on the surface properties of hair and its influence on hair damage. In this study, coacervates of different sizes were explored in 10% shampoo solutions; one solution contained coacervates with non-uniform sizes ($10-300{\mu}m$ average), and the other solution formed a coacervate with a fine and uniform ($1-3{\mu}m$) structure. To study the effect of shampoo on the physical properties of hair and damage to the hair, the hair breakage characteristics, color changes, friction properties, lipid contents and hair surface were examined after using two different types of shampoo. The results clearly show that the relatively fine and uniformly sized coacervate was evenly deposited over the surface of the hair. As a result, the coacervate system can substantially influence the surface properties of the hair such as hair friction, breakage characteristics, and color. The frictional force was dramatically reduced. The use of a fine and uniformly sized coacervate can notably improve hair surface properties. Consequently, hair breakage decreased, and the effect of the coacervate on hair damage was remarkably high.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.1
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• pp.99-110
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• 2012

Comparison on the genomic structure and phylogenetic relationship of the Hsp88 genes from P. tenuipes Jochoen-1, P. tenuipes, C. militaris and C. pruinosa was described. The Hsp88 genes from the three entomopathogenic strains, P. tenuipes Jocheon-1(strain), P. tenuipes(original species), and C. militaris contain the identical genomic structure, namely 5 introns and 6 exons with the length of 13, 62, 32, 1,438, 306, 288 nucleotides encoding 713 amino acid residues, whereas in case of C. pruinosa, it contains 4 introns and 5 exons with the length of 13, 62, 32, 1,744, 288 nucleotides encoding 713 amino acid residues. The genomic DNA length of the Hsp88 genes from P. tenuipes Jocheon-1 and P. tenuipes are both 2,600 nucleotides long in size. The Hsp88 genes from C. militaris and C. pruinosa are 2,582, 2,576 nucleotides long in size, respectively. Hsp88 genes of the P. tenuipes Jochoen-1, P. tenuipes, C. militaris and C. pruinosa also contain the conserved ATP-binding domain. Phylogenetic analysis of the Hsp genes of the four strains tested in this study showed that the fungal Hsp88 is divided into two separate clades, ascomycetes and deutromycete. Within the ascomycetes fungal clade, the P. tenuipes Jochoen-1 and P. tenuipes formed a subgroup, on the other hand, C. militaris and C. pruinosa formed another subgroup. Pair-wise comparison of P. tenuipes Jocheon-1 Hsp88 with those of P. tenuipes, C. militaris and C. pruinosa Hsp88s revealed significant identity in deduced amino acid sequence among these strains. The P. tenuipes Jocheon-1 Hsp88 showed 99% identity with the P. tenuipes, 97% identity with the C. militaris, and 98% identity with the C. pruinosa.

• Journal of Veterinary Clinics
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• v.33 no.5
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• pp.278-285
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• 2016

Epidemiological studies have shown the association between transportation of live animals and the potential transmission of infectious disease between premises. This finding was also observed in the 2014-2015 foot-and-mouth disease (FMD) outbreak in Korea. Furthermore, slaughterhouses played a key role in the global spread of the FMD virus during the epidemic. In this context, in-depth knowledge of the structure of direct and indirect contact between slaughterhouses is paramount for understanding the dynamics of FMD transmission. But the social network structure of vehicle movements to slaughterhouses in Korea remains unclear. Hence, the aim of this study was to configure a social network topology of vehicle movements between slaughterhouses for a better understanding of how they are potentially connected, and to explore whether FMD outbreaks can be explained by the network properties constructed in the study. We created five monthly directed networks based on the frequency and chronology of on- and off-slaughterhouse vehicle movements. For the monthly network, a node represented a slaughterhouse, and an edge (or link) denoted vehicle movement between two slaughterhouses. Movement data were retrieved from the national Korean Animal Health Integrated System (KAHIS) database, which tracks the routes of individual vehicle movements using a global positioning system (GPS). Electronic registration of livestock movements has been a mandatory requirement since 2013 to ensure traceability of such movements. For each of the five studied networks, the network structures were characterized by small-world properties, with a short mean distance, a high clustering coefficient, and a short diameter. In addition, a strongly connected component was observed in each of the created networks, and this giant component included 94.4% to 100% of all network nodes. The characteristic hub-and-spoke type of structure was not identified. Such a structural vulnerability in the network suggests that once an infectious disease (such as FMD) is introduced in a random slaughterhouse within the cohesive component, it can spread to every other slaughterhouse in the component. From an epidemiological perspective, for disease management, empirically derived small-world networks could inform decision-makers on the higher potential for a large FMD epidemic within the livestock industry, and could provide insights into the rapid-transmission dynamics of the disease across long distances, despite a standstill of animal movements during the epidemic, given a single incursion of infection in any slaughterhouse in the country.

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.51-59
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• 2018

The Multi-Mission Unmanned Surface Vehicle(MMUSV), which is manufactured using glass Fiber Reinforced Plastic(FRP) material, is designed to perform a surveillance and reconnaissance on the sea. Various navigation sensors, such as RADAR, RIDAR, camera, are mounted on a mast to perform an autonomous navigation. And a dummy gun is mounted on the deck of the MMUSV for a target tracking and disposal. It is necessary to analyze a strength for structures mounted on the deck because the MMUSV performs missions under a severe sea state. In this paper, a strength analysis of the mast structure is performed on static loads and lateral external loads to verify an adequacy of the designed mast through a series of simulations. Based on the results of captive model tests, a strength analysis for a heave motion of the mast structure is conducted using a simulation tool. Also a simulation and fatigue test for a mounting part between the MMUSV and the dummy gun are performed using a specimen. The simulation and test results are represented that a structure of the mast and mounting part of the dummy gun are appropriately designed.he impact amount are performed through simulation and experiments.