• Korean Journal of Plant Resources
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• v.33 no.2
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• pp.63-72
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• 2020

Fermented complex from garlic and nine medicinal plants were developed as a natural whitening material. Tyrosinase inhibition activity was determined and four active compounds were isolated. The nutritional components of fermented garlic complex (FGC) were analyzed to confirm the applicability as a functional food material. Tyrosinase inhibitory effect of FGC was 88.6%. Methanol extract was partitioned with EtOAc, n-BuOH and H₂O. From the EtOAc fraction (47 g), which showed the highest yield, active fractions were separated by repeated TLC, silica gel and ODS column chromatography to isolate active compounds. The chemical structures of the isolated compounds were analyzed by NMR and MS spectra. Phenylpropanoid compounds of 2,4,5-trihydroxy-benzenepropanoic acid (1) (1.9 mg) and 2,3,5-trihydroxy-benzenepropanoic acid (2) were confirmed. In addition, 2,4-dihydroxy-hydrocinnamic acid (3) (3.3 mg) and (+)sesamin (4) (6.1 mg) were isolated. These compounds will be useful as index compounds or functional compounds in FGC.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.365-373
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• 2006

This study suggested correction of excessive mouth opening or maximum occlusal contact to analyse occlusal contact time, occlusal contact number and force through evaluation of occlusal pattern in policemen with temporomandibular disorders. The community of policemen influence on temporomandibular disorder's development and progress due to other condition of mouth opening and maximal occlusal contact. Repeated training or changes of usual life style may cause imbalance of stomatognathic system including the masticatory muscle, then develop or aggravate pain of temporomandibular joints and associated structures. This study uses T-scan II system(Tekscan Co., USA) for evaluation on occlusal pattern may influence temporomandibular disorders, and then the subjects take a sensor at 20 mm opening for maximal occlusal contact force. The policemen with temporomandibualr disorders get more long time on maximum contact timing, more short on end contact timing, and more force on end contact force than general society's. So they get closure of mouth with more short time and more force, then transfer remaining load to temporomandibular joint. There are no statistically significances between affected side and occlusal pattern of occlusal contact time and force. There are Left -right dental arch imbalances seems on Rt. dental arch if affected side is right and Lt. dental arch if affected side is left. In above results, It's worth due consideration that policemen with temporomandibular disorders get more smooth mandibualr movement and less force on maximal occlusal contact position.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.2
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• pp.81-93
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• 2020

The fatigue characteristics of glass fiber reinforced plastic (GFRP) composites were studied under repeated loads using the finite element method (FEM). To realize the material characteristics of GFRP composites, Digimat, a mean-field homogenization tool, was employed. Additionally, the micro-structures and material models of GFRP composites were defined with it to predict the fatigue behavior of composites more realistically. Specifically, the fatigue characteristics of polybutylene terephthalate with short fiber fractions of 30wt% were investigated with respect to fiber orientation, stress ratio, and thickness. The injection analysis was conducted using Moldflow software to obtain the information on fiber orientations. It was mapped over FEM concerned with fatigue specimens. LS-DYNA, a typical finite element commercial software, was used in the coupled analysis of Digimat to calculate the stress amplitude of composites. FEMFAT software consisting of various numerical material models was used to predict the fatigue life. The results of coupled analysis of linear and nonlinear material models of Digimat were analyzed to identify the fatigue characteristics of GFRP composites using FEMFAT. Neuber's rule was applied to the linear material model to analyze the fatigue behavior in LCF regimen. Additionally, to evaluate the morphological and mechanical structure of GFRP composites, the coupled and fatigue analysis were conducted in terms of thickness.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.4
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• pp.731-742
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• 2018

Recently, the construction of the urban area has been rapidly increasing, and the excavation work of the ground has been frequently performed at the upper part of the existing underground structure. Especially, when the structure is constructed after the excavation of the ground, the loading and unloading process is repeated in the lower ground of the excavation so that it can affect existing underground structures. Therefore, in order to maintain the stability of the existing underground structure due to the excavation of the ground, it is necessary to accurately grasp the influence of the excavation and the structure load in the adjoining part. In this study, the effects of the ground excavation and the new structure load on the existing tunnel were investigated by large - scale experiment and numerical analysis. For this purpose, a large model tester with a size reduced to 1/5 of the actual size was constructed, and model tests and numerical analyzes were carried out to investigate the effects of the excavation of the body ground by maintaining the distance between the excavation floor and the tunnel ceiling constant, The impacts were identified. As a result of the study, it was confirmed that the deeper the excavation depth, the larger the influence on the existing tunnel. At the same distance, it was confirmed that the tunnel displacement increased with the increase of the building load, and the ground stress increased up to 2.4 times. From this result, it was confirmed that the effect of the increase of the underground stress on the existing tunnel is affected by the increase of the building load, and the influence of the underground stress is decreased from the new load width above 3.0D.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.2
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• pp.125-131
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• 2020

In this study, the author comparatively analyzed the effects and applicability of drifts, one of planting design methods based on the principle of visual harmony, to look into the definition and characteristics in planing techniques with examples of drifts in gardens designed by Gerturde Jekyll and Piet Oudolf. Sites chosen for the case studies included Jekyll's Upton grey and Hestercomb garden and Oudolf's At Scampston Hall and Trentham Estate Garden. The results showed that Jekyll set layers for vertical and horizontal structures by using plants of different height to make flowers look like floating with their stems unseen and appear in turn over time. Assemble planting of groups was used to conceal rigid, irregular lines so that the plants are recognized as mass with smoother horizontal lines. Clearly visible, repeated drifts creates a sense of unity. Oudolf, in combining grass and perennial plants, used one-to-one correspondence or expansion to express drifts. Grass serves roles as a connecting material inserted when changing space or making transitions of images. Blocks in single species are repeatedly crossed to set scenes, and overlapping and mixing makes them more lively.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.485-498
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• 2015

Structural analysis for a large-scale fault in Maegok-dong, Ulsan, was carried out based on filed-works to investigate the geometric and kinematic characteristics of the fault as well as its Quaternary slip. As results, a series of repeated stratigraphy, minor faults, fracture zones, and deformation band clusters are observed over a distance of about 100 m in the first studied site consisting of sedimentary rocks, which may indicate the damage zone of a large-scale fault in this site. In the second site, mainly composed of granitic clastic rocks, a large-scale thrust fault is expected based on low-angle dipping faults showing branched and/or merged patterns. Age of the last slip on this fault was restrained as after 33,275 ± 355 yr BP based on radiocarbon dating for organic material included in the gouge zone. Dimension of fault damage zone, dominant sense of slip, and age of the slip event associated with the fault suggest that these structures have a close relationship with the Ulsan Fault and/or Yeonil Tectonic Line, which are well-known large-scale neotectonic structural features around the study area. Therefore, it is necessary to study the characteristics of the faults in detail based on structural geology and paleoseismology in order to ensure seismic and geologic stability of the buildings under construction, and to prevent geologic hazards in this area.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.6
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• pp.541-549
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• 2008

The fatigue analysis is performed to avoid structural failure in aerospace structures under repeated loads. In this paper, the fatigue life is estimated for the design of tilt rotor UAV. First of all, the fatigue load spectrum for tilt rotor UAV is generated. Fatigue analysis is done for the flaperon joint which may have FCL(fracture critical location). Tilt rotor UAV operates at two modes: helicopter mode such as taking off and landing; fixed wing mode like cruising. To make overall fatigue load spectrum, FELIX is used for helicopter mode and TWIST is used for fixed wing mode. The other hand, the Kriging meta model is used to get S-N regression curve for whole range of material life when S-N test data are analyzed. And then, the second order of S-N curve is accomplished by the least square method. In addition, the coefficient of determination method is used to ensure how accuracy it has. Finally, the fatigue life of flaperon joint is compared with that obtained by MSC. Fatigue.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.57-62
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• 2007

The fruiting body of Phellinus linteus was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2$O. The repeated silica gel and ODS column chromatographies of the EtOAc fraction led to isolation of four sterols. From the result of spectral data including NMR, MS and IR, the chemical structures of the sterols were determined as ergosta-7,24(28)-dien-3${\beta}$-ol (episterol, 1), 5${\alpha}$,8${\alpha}$-epidioxyergosta-6,9(11),22-trien-3${\beta}$-ol (dehydrop-eroxyergosterol, 2), 5${\alpha}$,8${\alpha}$-epidioxyergosta-6,22-dien-3${\beta}$-ol (ergoterol peroxide, 3), and $3{\beta}$,$5{\alpha}$-dihydroxy-6${\beta}$-methoxyergosta-7,22-diene (6-O-methylcerevisterol, 4). The ergosterols have been first isolated from this mushroom in this study.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.65-69
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• 2008

The roots of Brassica campestris ssp rapa were extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$. From the EtOAc fraction, three compounds were isolated through the repeated silica gel and octadecyl silica gel (ODS) column chromatography. From the results of spectroscopic data including NMR and MS, the chemical structures of the compounds were determined as caulilexin C (1), indoleacetonitrile (2) and arvelexin (3). The arvelexin (3) has been isolated from this plant for the first time. Compounds 1, 2 and 3 showed inhibitory activity on human Acyl CoA: cholesterol. transferase 1 (hACAT1) by $54.6{\pm}6.0%$, $69.2{\pm}4.7%$ and $68.6{\pm}3.7%$, and on human Acyl CoA: cholesterol transferase 2(hACAT2) by $4.8{\pm}13.4%$, $45.6{\pm}4.8%$ and $39.5{\pm}4.3%$, respectively, at 100 ${\mu}g/ml$.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.165-175
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• 2009

With the current move towards adopting mechanistic-empirical concepts in the design of pavement structures, state-of-the-art mechanistic analysis methodologies are needed to determine accurate pavement responses, such as stress, strain, and deformation. Previous laboratory studies of pavement foundation geomaterials, i.e., unbound granular materials used in base/subbase layers and fine-grained soils of a prepared subgrade, have shown that the resilient responses followed by nonlinear, stress-dependent behavior under repeated wheel loading. This nonlinear behavior is commonly characterized by stress-dependent resilient modulus material models that need to be incorporated into finite element (FE) based mechanistic pavement analysis methods to predict more realistically predict pavement responses for a mechanistic pavement analysis. Developed user material subroutine using aforementioned resilient model with nonlinear solution technique and convergence scheme with proven performance were successfully employed in general-purpose FE program, ABAQUS. This numerical analysis was investigated in predicted critical responses and domain selection with specific mesh generation was implemented to evaluate better prediction of pavement responses. Results obtained from both axisymmetric and three-dimensional (3D) nonlinear FE analyses were compared and remarkable findings were described for nonlinear FE analysis. The UMAT subroutine performance was also validated with the instrumented full scale pavement test section study results from the Federal Aviation Administration's National Airport Pavement Test Facility (FAA's NAPTF).