• Journal of Korean Medicine for Obesity Research
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• v.15 no.2
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• pp.104-110
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• 2015

Objectives: The herb of Agastache rugosa (AR) is a traditional herbal medicine used for colds, vomiting and furuncles. However, there are few reports to investigate the inhibitory effects of AR on obesity. In this study, the effects of AR on high fat diet (HFD)-induced obesity and its mechanism of actions were investigated in experimental animals. Methods: The mice were fed HFD for 4 weeks to induce obesity. After randomly divided into normal fat diet, HFD and AR groups, 200 mg/kg of AR was administrated for 4 weeks with continuous HFD feeding while vehicle was orally treated to HFD group. Food intake and body weight were recorded weekly. Results: Increased body weight by HFD was improved by AR treatment. AR administration inhibited an increase of visceral fat weight as well as adipocyte hypertrophy. Hepatic steatosis was ameliorated in AR-treated mice. In addition, treatment of AR attenuated the expression of adipogenic transcription factor, peroxisome proliferator-activated receptor (PPAR)-gamma in the epididymal adipose tissue. Also the increased serum leptin level by HFD was maintained in AR group, leading to inhibition of food intake. Conclusions: AR treatment showed inhibitory effects on HFD-induced obesity by inhibition of PPAR-gamma and reduction of food intake. AR could be an alternative treatment for obesity.

• The Journal of the Petrological Society of Korea
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• v.14 no.1
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• pp.38-44
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• 2005

Hornblende $^{40}Ar/^{39}Ar$ age of $113.4{\pm}2.4(2{\sigma})$ Ma was determined from the volcanic pebble of the Silla Conglomerate which belongs to the Hayang Group of the Cretaceous Gyeongsang Supergroup. This age corresponds to the top of Aptian. Based on the reported age information, onset and duration of deposition of the constituting formations of the Hayang Group are constrained as follows; deposition of the Jindong Formation started from ca. 96~97 Ma and lasted for about 15 Ma. Therefore, Jindong Formation was deposited since Cenomanian to Santonian and it is likely to be extended to the early Campanian. We propose 81~80 Ma, which is in early Campanian, as the boundary between Hayang and Yucheon Groups. We suggest that the Silla Conglomerate was deposited during the early Albian and the Haman Formation was deposited during the rest of the Albian and also during the Cenomanian. The Chilgok Formation seems to be deposited during the late Aptian.

• Proceedings of the Petrological Society of Korea Conference
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• 2002.05a
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• pp.1-38
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• 2002

옥천변성대 서남부지역은 변성이질암의 광물조합을 기준으로 남동부부터 북서방향으로 흑운모대, 석류석대, 십자석대의 3개의 변성광물분대로 나누어진다. Oh et al. (1995a)의 연구에서 보고된 남정석들은 산출되지 않는 것이 확인되었고 변성도는 흑운모대에서 석류석대를 거쳐 십자석대로 갈수록 증가한다. 쥬라기 화강암 접촉부의 국부적인 변성암류에서는 화강암에 의한 접촉변성작용에 의해 형성된 홍주석과 규선석이 산출된다. 흑운모대의 변성 압력-온도는 4.2 - 5.1 kb, 400 - 500 $^{\circ}C$이다. 십자석대의 정누대구조를 가지는 석류석과 석류석안의 사장석, 흑운모, 금흥석, 일메나이트포유광물의 공생관계로 추정한 압력-온도 (석류석 주변부: 7.0 - 8.0 kb, 550 - 620 $^{\circ}C$； 석류석 중심부: 4.0 - 5.0 kb, 420 - 520 $^{\circ}C$) 및 십자석대 내에서 후퇴변성작용 및 접촉변성작용 받은 석류석 주변부에 기록된 압력-온도 조건(약 2.0 - 3.0kb, 450 - 55$0^{\circ}C$)과 함께 옥천변성대 서남부지역의 변성암류가 시계방향의 압력-온도 경로를 겪었음을 지시한다. 연구지역 내에서 정밀 기재된 단면들에 대한 퇴적환경을 종합하면 대체 적으로 남동부에서는 천해성 환경이 인지되나 북서쪽으로 갈수록 대륙사면을 거쳐 분지 중심의 환경으로 전이되는 경향을 보인다. 이러한 퇴적상의 공간적 분포는 분지의 남동쪽보다 북서쪽의 침강이 우세하였던 것으로 해석될 수 있으며, 이는 곧 분지가 형성될 때 반지구대 (half graben) 형태로 분지가 열개 (rifting) 되었음을 의미한다. 각 변성분대에서 채취한 변성이질암으로부터 측정된 K-Ar 과 40Ar/39Ar 흑운모와 백운모 연대들은 149 - 167 Ma에 집중된다. 그리고 각 변성분대에서 동일시료에 대한 K-Ar 과 40Ar/39Ar 연대들은 동일시기를 지시함으로 연대적인 신뢰성을 확인 할 수 있었다. 옥천변성대 서남부지역의 변성암류를 관입하는 2개의 괴상의 화강암과 1개의 엽리화강암에서 얻어진 백운모와 흑운모들의 K-Ar 연대는 모두 156 Ma이며 옥천변성대 서남부지역의 변성이 질암의 연대와 유사하다. 이는 연구지역의 변성암류와 화강암류는 40Ar/39Ar 과 K-Ar 계의 흑운모와 백운모의 폐쇄온도 (약 300 - 350 $^{\circ}C$) 까지 동시에 냉각된 사실을 지시한다. 각섬석 편암내의 각섬석들은 복잡한 40Ar/39Ar 연대를 보여주며 일부가 평형연대를 보여주지만 특별한 의미 부여가 힘들다.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.853-856
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• 2005

Inductively coupled plasma reactive ion etching of magnetic tunnel junction (MTJ) stack, which is one of the key elements in magnetic random access memory, was studied. The MTJ stacks were patterned in nanometer size by electron(e)-beam lithography, and TiN thin films were employed as a hard mask. The etch process of TiN hard mask was examined using Ar, $Cl_2/Ar$, and $SF_6/Ar$. The TiN hard mask patterned by e-beam lithography was first etched and then the etching of MTJ stack was performed. The MTJ stacks were etched using Ar, $Cl_2/Ar$, and $BCl_3/Ar$ gases by varying gas concentration and pressure.

• Journal of the Korean Magnetics Society
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• v.8 no.6
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• pp.369-373
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• 1998

The exchange anisotropy between NiO antiferromagnetic layer and NiFe ferromagnetic layer has been investigated in NiFe(10 nm)/NiO(60 nm) formed by magnetron sputtering. The NiO films were sputtered from nickel oxide using R. F. poser and NiFe, Ta were deposited using D. C. power under Ar atmosphere. Above all. we studied the exchange anisotropy of Ni-Fe/NiO bilayer, and focused especially on the effect of NiO depostion condition. Our experimental data showed that the dominant factor for determining the exchange anisotropy properties was the Ar pressure during NiO deposition. The better exchange anisotropy properties were found when the NiO film was deposited at low Ar pressure probably due to the flatten interface and the epitaxial tendency of NiO grains and NiFe grains. However, as Ar pressure increased, interfacial diffusion at NiFe/NiO interface and oxygen content of NiO film increase, and consequently reduced the exchange anisotropy. We concluded that the flatten interface and relatively low oxygen content of NiO layer are dominant factors for the enhancement of the exchange anisotropy in NiFe/NiO bilayer.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.1-7
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• 2019

This study focused on the usability and the difference between VR and AR technology in the FEM/CFD simulation environments. First, this paper explains the current status and prospect of the VR/AR technology and conducted a case study on the VR and AR service in the FEM/CFD simulation environments. In addition, we made the evaluation strategies for usability by a review of previous research. And then, after Interviewers participants who use of simulation at a specific site C to we investigated the usability of the VR and AR service based on the mobile device in the FEM/CFD simulation environments. The result of this study is look forward to be used as a design service to form a VR and AR service in the future.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.161-170
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• 2023

In this study, our primary focus was on preserving the unique characteristics inherent to the medium of printmaking art, such as cultural implications and formal features, during the digital transformation of traditional printmaking. We investigated methods to incorporate augmented reality (AR) technology into the creation process of traditional printmaking. To help understand the intended fusion of traditional printmaking art and AR technology in this digital transition era, we categorized AR artworks into four types and conducted an analysis of various AR artwork examples from across the globe. From this analysis, we derived the methodologies and design directions for combining AR technology with traditional printmaking. Moreover, we created an AR printmaking piece based on the author's artwork "Spring, Summer, Fall, Winter," thereby demonstrating the significant role AR technology can play in the evolution of printmaking. Through this research, we were able to verify the potential and value of AR printmaking as an immersive art form capable of providing a more expansive narrative.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.81-92
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• 1996

The Ar/Ar-$H_2$ plasma method was applied to reduce oxides and refine metals of V, Ta and B. In addition, the high temperature chemical reaction in Ar plasma and of the refining reaction in the Ar-(20%)$H_2$ plasma were analyzed. The crude V of 96wt% purity was obtained at the ratio of $C/V_{2}O_{5}=4.50$ by the Ar plasma reduction grade and the maximum reduction was obtained at $C/V_{2}O_{5}=4.50$ due to the $O_{2}$ loss from the thermal decomposition of vanadium oxide. In the Ar-(20%)$H_2$ plasma refining, the metallic V of 99.2wt% was produced at the ratio of $C/V_{2}O_{5}=4.40$. It was considered that a main refining reaction resulted from the chemical reaction between the residual carbon and residual oxygen. The metallic Ta of 99.8wt% was obtained at the ratio of $C/Ta_{2}O_{5}=5.10$ in a Ar plasma reduction and the Oz loss from the thermal decomposition of tantalum pentoxide did not take place. The deoxidation reaction was more significant than the decarburization reaction in the Ar-(20%)$H_2$ plasma refining and the metallic Ta of 99.9wt% was produced within the range of $C/Ta_{2}O_{5}$ ratio of 4.50 to 5.10. The Vickers hardness of Ta in the above mentioned range was about 220Hv due to the decrease in a residual oxygen by the deoxidation reaction. On the other hand, C is no suitable agent for the reduction of $B_{2}O_{3}$ by the Ar and Ar-$H_2$ plasma. But Fe-B-Si alloy was produced with the reduction of $B_{2}O_{3}$ in the melt when Fe, C, $B_{2}O_{3}$, and ferroboron mixtures were melted by the high frequency induction melting.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.93-113
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• 2008

This study presents petrochemistry and $^{40}Ar/^{39}Ar$ absolute ages of subsurface volcanic rock cores from twenty(20) boreholes in the eastern lowland (altitude loom below) of Jeju Island, Handeong-Jongdal-Udo-Susan-Samdal-Hacheon areas, and discusses topography and volcanism in the area. The subsurface volcanic rock cores are mainly basalts in composition with minor tholeiitic andesites and basaltic trachyandesites. Sequences of intercalated tholeiitic, transitional and alkalic lavas suggest that tholeiitic and transitional to alkalic lavas must have erupted contemporaneously. Especially, occurrences of trachybasalts and basaltic trachyandesites at the bases in the area imply that the volcanism in the area was initiated with slightly differentiated alkaline magma activity. The $^{40}Ar/^{39}Ar$ absolute ages of the subsurface volcanic rock cores range from $526{\pm}23ka\;to\;38{\pm}4Ka$. The lava-forming Hawaiian volcanic activities of the eastern lowland can be divided into five sequences on the basis of sediment distribution, whole rock geochemistry and $^{40}Ar/^{39}Ar$ absolute ages of the subsurface volcanic rock cores; stage I-U$(550{\sim}400Ka)$, stage II$(400{\sim}300Ka)$ and stage III$(300{\sim}200Ka)$ during syn-depositional stage of Seoguipo Formation, and stage IV$(200{\sim}100Ka)$ and stage V(younger than 100Ka) during post-depositional stage. In the eastern lowland of Jeju Island, compositional variations and local occurrences of the subsurface volcanic rocks as well as existences of various intercalated sediment layers (including hydrovolcanogenic clasts) suggest that the volcanism must have continued for long time intermittently and that the land has been progressively glowed from inland to coast by volcanic activities and sedimentation. It reveals that the subsurface volcanic rocks in the eastern lowland of Jeju Island must have erupted during relatively younger than 200Ka of stages IV and V. The results of this study are partly in contrast with those of previous studies. This study stresses the need that previous reported volcanic activities in Jeju Island based on K-Ar ages of volcanic rocks should be carefully reviewed, and that stratigraphic correlation from boreholes should be conducted by quantitative criteria combined with petrography and petrochemstry as well as radiometric studies of volcanic rock cores.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.1
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• pp.106-113
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• 2002

In this paper, breakdown characteristics of pure Kr, Ar and $N_2$gas with gas pressure range were investigated, and the measured values were compared with those in Ar/$N_2$and Kr/$N_2$gas mixtures with pressure varying. Also, various characteristics with gas mixtures in practical incandescent lamps were investigated. Summarizing the experimental results, the breakdown voltages of $N_2$gas were increased than those of Kr and Ar gas with large molecular weight, and the breakdown voltage increased with gas pressure increasing. The breakdown voltages of Ar/$N_2$and Ar/$N_2$gas mixtures were decreased with decreasing the mixtures ratio of $N_2$gas, and corona inception voltage of Kr/$N_2$gas mixtures under non-uniform fields were increased than those of Ar/$N_2$gas mixtures. In case of tactical incandescent lamps, luminous and lifetime of Kr(70%)/$N_2$(30%) gas mixtures were increased about 94[lm] and 380[hr] than those of Ar(70%)/$N_2$(30%) gas mixtures. and injection pressure of gas mixtures with cooling temperature of 20[$^{\circ}C$] in incandescent lamps were increased about 13[%] than those with cooling temperature of 40[$^{\circ}C$].