• Title/Summary/Keyword: 형상특성

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Preparation and Characterization of Planar-type Artificial Calamine Powder with a High Aspect Ratio for the Application to Ultraviolet and Blue Band Protection Cosmetics (자외선 및 블루영역 차단 화장품 응용을 위한 박막 판형 인공 칼라민 소재의 합성 및 특성 평가 연구)

  • Lee, Jung-Hwan;Lee, Gun-Sub;Jo, Dong-Hyeon;Hong, Da-Hee;Yu, Jae-Hoon;Gwack, Ji-Yoo;Lee, Hee-Chul
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.47 no.3
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    • pp.227-235
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    • 2021
  • In this study, we have prepared pure planar-type ZnO and calamine powder containing both ZnO and Fe2O3 components as a raw material for cosmetics with UV and blue band blocking functions. The planar-type ZnO ceramic powder having a high aspect ratio in the range of 20:1 to 50:1 was synthesized by precipitation method in a zinc acetate and sodium citrate mixed solution with the electrolyte obtained by power generation with a zinc-air battery. The content of Fe2O3 in the artificial calamine ceramic powder could be increased by increasing the amount of iron chloride solution added, and in this case, some of the blue region of visible light and ultraviolet light were remarkably absorbed. When potassium acetate was added, the decomposition of the Zn(OH)42- anion in the solution was promoted to facilitate the growth of ZnO crystal in the form of a barrier wall in the vertical direction on the (0001) plane, which could increase UV absorption by providing more opportunities. By controlling the amount of iron chloride solution and potassium acetate solution added, the composition and shape of the thin film plate-shaped artificial calamine ceramic powder can be optimized, and when applied to cosmetic formulations, the light transmittance of the blue region can be greatly reduced.

Transient Heat Transfer Analysis and Fire Test for Evaluation on Fire Resistance Performance of A60 Class Deck Penetration Piece (A60급 갑판 관통 관의 방화성능 평가를 위한 과도 열전달 해석과 화재시험)

  • Park, Woo Chang;Song, Chang Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.1-9
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    • 2021
  • A60 class deck penetration piece is a fire-resistance apparatus installed on the deck compartment to protect lives and prevent flame diffusion in fire accidents. In case that the A60 piece is newly developed or its initial design is revised, it is important to verify the fire resistance performance using a fire test procedure (FTP) code. In this paper, transient heat transfer analysis was carried out to evaluate the fire resistance design compatibility of the newly devised A60 piece. The analysis results were verified via a fire test. The heat transfer characteristics were also investigated by comparing design specifications, such as diameter, internal configuration, and material type. The analysis was performed using ABAQUS/Implicit, and the fire test was performed according to the FTP code. The fire resistance performance of the A60 pieces satisfied the safety of life at sea convention regulation. The material type was the most important design specification for the A60 piece. Based on the maximum test temperature, the measured temperature of SUS316L material was 25% lower than that of S45C on average. The differences between thermal conductivity and specific heat of each material were 17% and 58%, respectively.

A Study on the Type Classification and Selection Methods of Archival Objects (행정박물의 유형분류 및 선별방안에 관한 연구)

  • Lee, Young-hak;Kim, Myoung-hun;Lim, Eun-jung
    • The Korean Journal of Archival Studies
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    • no.17
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    • pp.115-156
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    • 2008
  • Archival objects produced in relation to the activities of public institutions hold the inexpressible symbolism, historical value, and esthetical value as well in that the values of display and reuse of archives materials in the future are high as figures. The revised law of Archives Act in 2007 has provided a foundation for managing the archival objects in every public organization, by also including archival objects into the category of archives produced and registered in relation to their works. Although it could be seen as a reforming will to aim at the differential approach from the past to recognize the archival objects as records and make the managing will documented, it is still in an unprepared state to define the concepts on archival objects and to have methods to systematically manage and preserve them. Thus this paper has researched on the type classification of archival objects and their evaluation, as way of developing the methods for the management system for archival objects. On the premise that it should be preceded by clear definitions of concepts and distinctive understanding of their types first in order to build up the management system for archival objects, definition and type classification of the archival object have been attempted, based on the actual research materials and the current relevant laws. In addition, this study has analyzed the characteristics of selecting archival objects in order to search for which one they should obtain and manage among archival objects produced and reused in relation to the works of public institutions. On the basis of this, the plans for the national selection system and provision of selecting criteria for the subjects of permanent preservation have been suggested in this study.

A Study on the Selected acts of "Ba-Yi-ji" in Zui-bai-qiu focused on the characteristics of the performance (18세기 《팔의기八義記》 공연본 연구 - 『철백구綴白裘』 본 절자희折子戱를 중심으로 -)

  • Oh, Soo-kyung;Seo, Soo-min
    • (The) Research of the performance art and culture
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    • no.20
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    • pp.95-128
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    • 2010
  • 'The Orphan of Zhao family(Zhaoshi-Guer)'is one of the famous Chinese drama constantly transmitted for a long time from Yuan Dynasty to Qing Dynasty. The plot of the play in the transmitting process has not been changed much, but added new characters or episodes. The Kunqu, one of the Chinese drama styles was characterized by graceful music and refined literature, being very popular among the gentry of Ming and Qing Dynasty. The 'Zhaoshi-Guer' play in 'chuanqi' style of the 'The Sixty Plays' collection, is called 'Ba-yi-ji', which was sung in Kunqu崑曲 stage. Because 'The Sixty Plays' collection was widely read throughout the late Ming and Qing Dynasty, the 'The Sixty Plays' version became the model of Kunqu lineage example and so it was in the case of "Ba-yi-ji". In the end of the Ming, new performing type of drama that is called as Zhe-zi-xi(折子戱) was appeared. Zhe-zi-xi refers to make only some pieces, not the whole. With the new form of performance appeared many of the selected texts of plays have come out including 'Zui-bai-qiu'. Through the comparison between the pices of two Kunqu version, 'The Sixty Plays' and 'Zui-bai-qiu', I tried to observe the charisteristics of the Ba-Yi-ji performance of Qing dynasty. The latter succeded the former, but more performance oriented, such as using lively and easy word with the acting direction intensified and comic characters.

Performance Comparison of Matching Cost Functions for High-Quality Sea-Ice Surface Model Generation (고품질 해빙표면모델 생성을 위한 정합비용함수의 성능 비교 분석)

  • Kim, Jae-In;Kim, Hyun-Cheol
    • Korean Journal of Remote Sensing
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    • v.34 no.6_2
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    • pp.1251-1260
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    • 2018
  • High-quality sea-ice surface models generated from aerial images can be used effectively as field data for developing satellite-based remote sensing methods but also as analysis data for understanding geometric variations of Arctic sea-ice. However, the lack of texture information on sea-ice surfaces can reduce the accuracy of image matching. In this paper, we analyze the performance of matching cost functions for homogeneous sea-ice surfaces as a part of high-quality sea-ice surface model generation. The matching cost functions include sum of squared differences (SSD), normalized cross-correlation (NCC), and zero-mean normalized cross-correlation (ZNCC) in image domain and phase correlation (PC), orientation correlation (OC), and gradient correlation (GC) in frequency domain. In order to analyze the matching performance for texture changes clearly and objectively, a new evaluation methodology based on the principle of object-space matching technique was introduced. Experimental results showed that it is possible to secure reliability and accuracy of image matching only when optimal search windows are variably applied to each matching point in textureless regions such as sea-ice surfaces. Among the matching cost functions, NCC and ZNCC showed the best performance for texture changes.

Analysis of Instances of Characteristics Land Creep on the Mine Area in Korea (우리나라 광산지역에서의 땅밀림 사례 분석)

  • Park, Jae-Hyeon;Park, Seonggyun
    • Journal of Korean Society of Forest Science
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    • v.107 no.4
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    • pp.393-401
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    • 2018
  • The aim of this study was to analyze the characteristics of ground subsidence and land-creeping in four mining areas in Korea. Land creeping were occurred by large-scale sinkholes and tensile cracks in the mining areas. This ares showed the shape as large-scale landslides by the collapsed stone debris pushed in the direction of gravity. The rock type in the No. 4 survey area was sandstone and shale, whereas that of other three areas was limestone. The limestone was generally vulnerable to land creeping. The ground subsidence and land creeping in four mining areas were located near the ridge of the mountain. The land creeping by ground subsidence in the mining areas showed complex shapes due to the cavity of underground tunnel and the colluvial debris by gravity in the mountain area, whereas the land creeping in Korea are in the shape of landslide. The average slope of the mining area was ranged from $30.4^{\circ}$ to $33.7^{\circ}$. The values were higher ($1.5^{\circ}{\sim}4.8^{\circ}$) than the average slopes for landslide areas.

The Adequacy Assessment and Growth Effects by Methods of 1st Thinning in Chamaecyparis obtusa Forest (편백림의 1차 솎아베기 방법에 따른 생장효과와 적절성 연구)

  • Park, Joon Hyung;Son, Yeong-Mo;Lee, Kwang Soo;Park, Eun Jung;Jung, Su Young
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.349-356
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    • 2019
  • This study examines the effect of thinning in terms of changes in the growth characteristics of Chamaecyparis obtusa stands after they were thinned with varying intensity in Gochang, North Jeolla Province, Korea. Thinning was carried out in 2000 on Chamaecyparis obtusa stands (22 years old), and the stands were categorized in terms of the thinning intensity in the experiment: very heavy, heavy, medium, light, and control. The results of monitoring up to 2018 revealed that the diameter at breast height and the growth rate of individual trees after thinning had a positive correlation with the thinning intensity, whereas the stand volume showed a negative correlation. The height to diameter (H/D) ratio decreased by up to 70-80 due to the increased diameter at breast height after thinning and thereby resulted in better quality. The relative yield index right after the first thinning was between 0.75 and 0.95, which suggests the best timing for the first thinning had been missed. This study's findings are expected to serve as a basic reference in establishing the thinning system for Chamaecyparis obtusa forests.

Analytical Research on Dynamic Behavior of Steel Composite Lower Railway Bridge (강합성 하로 철도교의 동적거동에 대한 해석적 연구)

  • Jeong, Young-Do;Koh, Hyo-In;Kang, Yun-Suk;Eom, Gi-Ha;Yi, Seong-Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.1
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    • pp.27-35
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    • 2019
  • The existing middle-long span railway bridge has been mainly applied to steel box girder bridges. However, the steel box girder bridges have disadvantages in securing the space under the bridge, and the main girder is made of a thin plate box shape, resulting in a ringing noise due to the vibration. Many complaints about noise have been raised. For this reason, there is a need for the development of long railway bridges that can replace steel box girder bridges. In this paper, the characteristics of the steel composite railway bridge currently developed were introduced and a time history analysis was conducted using MIDAS Civil reflecting the speed of KTX load for 40m and 50m bridges. In addition, from the analysis results, the dynamic behavior of target bridges were verified and it was examined whether they meet the dynamic performance criteria proposed in the railway design standards. As a result, all of the bridges under review satisfied the dynamic safety criteria, however, in case of 40m of span, the vertical acceleration value was very large. In order to solve this problem, authors proposed the improvement plan and corrected the cross section to confirm that the vertical acceleration decreased.

Development Status of Technology Demonstration Model for Staged Combustion Cycle Engine (다단연소사이클 엔진 기술검증시제 개발 현황)

  • Kim, Chaehyoung;Lee, Jungho;Woo, Seongphil;So, Younseok;Yi, SeungJae;Lee, Kwang-Jin;Cho, Namkyung;Han, Yeoungmin;Kim, Jin-han
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.4
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    • pp.104-111
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    • 2019
  • Staged combustion cycle engines exhibit higher combustion performance compared with open cycle engines with a gas generator. An advanced research of the staged combustion cycle engine is going on for the next program following the KSLV-II program. Various experiments have been carried out for the technology demonstration model, TDM0A and TDM0B. The experiments on the combustion performance are aimed to understand the engine start condition and combustion characteristics. They also aim to develop the oxidizer-rich pre-burner and the combustor of the staged combustion cycle engine. The engine-shaped model, TDM1A is fabricated based on the experimental data. The combustion experiment of the TDM1A shows that the combustion pressure of the combustor is approximately 91 bar and the turbine rotation is approximately 28,00 rpm. The result is stable and satisfies the development requirements. The present paper reports on the development process and characteristics of engine models from TDM0A to TDM1A.

Experimental Study on the Effect of the Area Ratio between Shaft and Tunnel and Heat Release Rate on the Plug-holing Phenomena in Shallow Underground Tunnels (저심도 도로터널에서 터널과 수직환기구의 단면적 비와 열방출률이 Plug-holing 현상에 미치는 영향에 관한 실험연구)

  • Hong, Kibea;Na, Junyoung;Ryou, Hong Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.619-625
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    • 2019
  • It is difficult to design because of the plug-holing phenomenon in which the amount of smoke discharged from the vertical vent is smaller than the designed amount of smoke. In this study, the effect of cross-sectional area ratio of tunnel and natural ventilation and heat release rate of fire source on plug-holing phenomenon occurring in natural ventilation system was experimentally analyzed. In the experiment model reduced to 1/20 size, the aspect ratio of the tunnel and the vertical vent was fixed, and the influence on the plug-holing phenomenon was confirmed by varying the sectional area ratio of the tunnel and the vertical vent. Experimental results show that the plug-holing phenomenon is caused by the comparison of the smoke boundary layer temperature with the temperature in the vertical vents, and the flow and temperature distribution characteristics under the vertical vents are changed as the cross-sectional area ratio of the tunnel and vertical vents increases. The plug-holing phenomenon is affected by the cross-sectional area ratio between the tunnel and the vertical ventilation. The greater the cross-sectional area ratio, the greater the probability of plug-holing.