• Journal of Powder Materials
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• v.27 no.1
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• pp.37-43
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• 2020

The Fe-22wt.%Cr-6wt.%Al foams were fabricated via the powder alloying process in this study. The structural characteristics, microstructure, and mechanical properties of Fe-Cr-Al foams with different average pore sizes were investigated. Result of the structural analysis shows that the average pore sizes were measured as 474 ㎛ (450 foam) and 1220 ㎛ (1200 foam). Regardless of the pore size, Fe-Cr-Al foams had a Weaire-Phelan bubble structure, and α-ferrite was the major constituent phase. Tensile and compressive tests were conducted with an initial strain rate of 10^-3/s. Tensile yield strengths were 3.4 MPa (450 foam) and 1.4 MPa (1200 foam). Note that the total elongation of 1200 foam was higher than that of 450 foam. Furthermore, their compressive yield strengths were 2.5 MPa (450 foam) and 1.1 MPa (1200 foam), respectively. Different compressive deformation behaviors according to the pore sizes of the Fe-Cr-Al foams were characterized: strain hardening for the 450 foam and constant flow stress after a slight stress drop for the 1200 foam. The effect of structural characteristics on the mechanical properties was also discussed.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.511-520
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• 2009

In this study, the Ocean Tide Loading (OTL) constituents were detected by the Precise Point Positioning (PPP) technique using GPS. Then, the GPS estimates of OTL constituents were compared with the predictions of the ocean tide models. We picked three permanent GPS stations as test sites and they are ICNW, SEOS, and CJUN. To detect the OTL constituents using GPS, we created vertical coordinate time series at 10-minute intervals using the PPP approach implemented in the GIPSY software. Through the tidal harmonic analysis of this height time series, the four major constituents ($M_2$, $S_2$, $K_1$, $O_1$) were determined. The amplitude obtained from the GPS height time series of the OTL constituents showed best match with the model predictions at CJUN, while the phase showed closest match at ICNW. The amplitude accuracy of the $M_2$, which is the dominant factor out of the 11 major constituents, was 24.8% on average.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.420-431
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• 2018

This study approaches the subject of satisfaction and persistent use intention based on presence based on virtual reality (VR). VR presence, user characteristic, and VR sickness, content satisfaction and system satisfaction, and continued use intention through this of 569 men and women commissioned by the survey agency were investigated. In the content of the study, the constituent factors of VR presence, an independent variable, were set as realism, immersion, and interaction. The user characteristics were set as the individual 's propensity to innovate, the degree of immersion, and the experience of using VR. VR Presence, User Characteristics, VR Sickness of Intention of Continuous Usage were set as research problems and models. Eight hypotheses were adopted in the analysis of the research problem applying the structural equation modeling (SEM) model. In conclusion, this study suggests that content satisfaction, which has the greatest influence on VR content satisfaction and persistent intention, is suggested.

• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.115-120
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• 1999

This study was carried out to compare the essential oil and its composition, and estragol content at different growth stages in the local collections of A. rugosa. Estragol was the major constituent in essential oil of all collections tested. Estragol content in essential oil was $82.3{\sim}89.1%$ in leaves, $81.1{\sim}89.2%$ in inflorescence, $72.0{\sim}45.2%$ in stem and there was no significant difference among nine local colletions. At full bloom stage, essential oil content was significantly higher than other growth stages and the highest content of estragol in essential oil was appeared at this stage. Especially, the content of essential oil in the inflorescence of Mokpo collection was 3.3%, which was the highest among the collections. Mokpo and Jindo collections produced much more essential oil and estragol than the other collections both at full bloom and ripening stages.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.45-49
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• 2006

Fumigant toxicity of four plant essential oils (muguet flower, patchouli, pennyroyal, spearmint) were tested against the adults of western flower thrips, Frankliniella occidentalis. Among them, pennyroyal and spearmint oils showed 100% mortality at $1{\mu}{\ell}/45m{\ell}$ air dose. Through the constituent analysis using GC and GC-MS, we confirmed that main constituents of pennyroyal oil were pulegone(100.0%), and spearmint oil were $\beta-myrcene(3.5%)$, limonene(12.1%), carvone(85.4%). Among them, carvone and pulegone showed 100% fumigation at $1{\mu}{\ell}/45m{\ell}$ air dose, respectively. It can concluded that two oils are potential control agents against F. occidentalis.

• International Journal of Human Ecology
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• v.7 no.1
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• pp.37-52
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• 2006

This study was designed to analyze the three-dimensional shapes of Hanbok Chima made with various fabrics and to clarify the relationship between fabric properties as well as the objective and subjective evaluations of the 3D shape. For 3D shape data, a dress form (9A2 (N; nude)) was scanned with eight Chima garments made with the same number of fabrics. The scanner used was a non-contact three-dimensional human body measuring system belonging to Bunka Women's University in Japan. Data concerning the objective evaluation of the 3D shape was obtained from the measurements of the vertical and horizontal sections: those for subjective evaluation were through the sensory test after exposure to photographs from a front and side view. Four fabric factors were extracted from fabric physical properties: softness, extension, thickness of threads, and weight of fabric. Such factors as expansion (volume), sag of rear train, shape of nodes were influential in explaining the 3D shape of Hanbok Chima. From the analysis of the 3D shape, it can be deduced that with the constituent fabric stiffer, lighter, and less stretchable, the more expanded the 3D shape appeared to be. Multiple regression results showed that vertical shape factors have a greater effect on the evaluation of the 3D shape. It also implies that dependent variables of this study such as the subjective evaluation and 3D shape can be derived from regression equations on independent variables as fabric property factors or 3D shape factors. These results can enable the manufacturers to predict the 3D shape of the garment as well as the human subjective assessment to improve the efficacy of production. The investigation method proposed in this study can also be applicable to other garment items.

• Journal of the Korean School Mathematics Society
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• v.13 no.4
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• pp.655-678
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• 2010

In the elementary mathematics, geometric education emphasize spatial sense and understandings of figures through development of intuitions in space. Especially space visualization is one of the factors which try conclusion with geometric problem solving. But studies about space visualization are limited to middle school geometric education, studies in elementary level haven't been done until now. Namely, discussions about elementary students' space visualization process and methods in plane or space figures is deficient in relation to geometric problem solving. This paper examines these aspects, especially in relation to plane and space problem solving in elementary levels. First, we investigate visualization methods for plane problem solving and space problem solving respectively, and analyse in diagram form how progress understanding of figures and visualization process. Next, we derive constituent factor on visualization process, and make a check errors which represented by difficulties in visualization process. Through these analysis, this paper aims at deriving an influence of visualization on geometric problem solving in the elementary mathematics.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1277-1283
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• 2002

Silsosangami(SSG) is a formula of treaditional korean medicines as an effective biological response modifier for augmenting host homeostasis of body circulation. Little is known of the biological activity of SSG and previous studies have focused mainly on their anti-thrombosis8). There is a growing interest in the pharmacological potential of the SSG due to the recent finding by our group that SSG and each constituent herbs of SSG were able to inhibit NO and prostaglandin E2 (PGE2) synthesis in murine peritoneal macrophages stimulated with bacterial endotoxin. In this paper, the effects of SSG on platelet aggregation and hemolysis in human blood were studied. SSG provoked remarkable inhibiting effect on platelet aggregation, and APTT were sensitive to the presence of this SSG. Using an in vitro system, APTT was delayed with the increment of the concentrations of these seven compounds. These results suggested that SSG might be used as a novel antithrombotic therapeutic agents in post-myocardial infarction. A SSG reduced NO production in mouse peritoneal macrophages stimulated with lipopolysaccharide, without the influence on the activity of iNOS being observed. SSG significantly reduced mouse paw edema induced by carrageenan. Western blot analysis showed that SSG reduced the expression of iNOS. The results indicate that SSG exerts anti-inflammatory effects related to the inhibition of NO production, which could be due to a decreased expression of iNOS.

• Geomechanics and Engineering
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• v.4 no.3
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• pp.173-190
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• 2012

With recent growing interests in the Performance-Based Seismic Design and Assessment Methodology, more realistic modeling of a structural system is deemed essential in analyzing, designing, and evaluating both newly constructed and existing buildings under seismic events. Consequently, a shallow foundation element becomes an essential constituent in the implementation of this seismic design and assessment methodology. In this paper, a contact interface fiber section element is presented for use in modeling soil-shallow foundation systems. The assumption of a rigid footing on a Winkler-based soil rests simply on the Euler-Bernoulli's hypothesis on sectional kinematics. Fiber section discretization is employed to represent the contact interface sectional response. The hyperbolic function provides an adequate means of representing the stress-deformation behavior of each soil fiber. The element is simple but efficient in representing salient features of the soil-shallow foundation system (sliding, settling, and rocking). Two experimental results from centrifuge-scale and full-scale cyclic loading tests on shallow foundations are used to illustrate the model characteristics and verify the accuracy of the model. Based on this comprehensive model validation, it is observed that the model performs quite satisfactorily. It resembles reasonably well the experimental results in terms of moment, shear, settlement, and rotation demands. The hysteretic behavior of moment-rotation responses and the rotation-settlement feature are also captured well by the model.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.533-542
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• 2014

We extracted essential oils from four species (Pinus densiflora, Larix kaempferi, Pinus koraiensis, and Abies holophylla) in the family Pinaceae to investigate their antibacterial activities against respiratory tract bacteria (Klebsiella pneumoniae, Haemophillus influenzae, Streptococcus pyogenes, Streptococcus pneumonia, and Neisseria meningitides). Among the tested oils, that from A. holophylla was showed strong activity based on disc diffusion and broth medium dilution (minimum inhibitory concentration, MIC) assays. Qualitative analysis of A. holophylla oil was carried out by GC-MS; ${\alpha}$-pinene, camphene, ${\beta}$-pinene, 3-carene, limonene, bornyl acetate, borneol, ${\beta}$-caryophyllene, ${\alpha}$-caryophyllene, caryophyllene oxide, and ${\alpha}$-bisabolol were identified as its major constituents. Fractionation by silica gel chromatography was performed to analyze the active constituents of the crude oil. In particular, one fraction containing caryophyllene oxide as the major constituent showed stronger antibacterial activity than the crude oil of A. holophylla. Growth rates of bacterial strains exposed to fraction D were explored by optical density (OD600) measurements while morphology was examined by optical microscopy observations ( ${\times}1000$). OD600 of K. pneumoniae decreased from 0.2582 to 0.005 in response to treatment with fraction D at a MIC value of $0.31{\mu}{\ell}/m{\ell}$.