기계적 합금화법으로 제조된 과포정 Al-Ti합금에서 Al3Ti 형성에 관한 연구

김혜성,서동수,김긍호,금동화 ( Hye Sung Kim,Dong Soo Suhr,Gyeung Ho Kim,Dong Wha Kum ) 한국열처리공학회 1996 熱處理工學會誌 Vol.9 No.1

Mechanical alloying is an effective process to finely distribute inert dispersoids in an Al-TM(TM is a transition metal) system. It has been considered that high melting point aluminides are formed by precipitation from supersaturated Al(Ti) powder. This analysis is based on the fact that much higher content of TM than the solubioity can be dissolved in alpha aluminum during the high energy ball milling. Thus, decomposition behavior of Ti in the Al(Ti) was considered very important. But it is confirmed that the higher portion of Ti than Al(Ti) solid solution is existed as nano-sized Ti particles in the MA powders by high energy ball nilling from the XRD spectrum and TEM analysis in this study. Therefore, the role of undissolved TM particles affect the formation of aluminides should be suitably considered. In this study, we present experimental observation on the formation of Al₃Ti fron mechanical alloyed Al-Ti alloys in the hyperperitectic region. This study showed that, in the mechanically alloyed Al-20wt%Ti specimen, intermediate phase of cubic Al₃Ti and tetragonal Al_(24)Ti_8 formed at 300∼400℃ and 400∼500℃, respectively, before the MA state reaches to equilibrium at higher temperatures. The formation behavior of Ll₂-Al₃Ti is interpreted by interdiffusion of A1 and Ti in solid state based on the fact that large amount of nano-sized Ti particles exist in the milled powder. Present analysis indicated undissolved Ti particles of nanosize should have played an important role initiation the formation of Al₃Ti phase during annealing.

가스분사 분말로부터 고온 압출된 Al-Ni-Mm-(Cu, Fe)합금들의 미세구조 및 기계적 성질

김혜성,Kim, Hye-Sung 한국재료학회 2006 한국재료학회지 Vol.16 No.2

The effects of Cu and Fe additions on the thermal stability, microstructure and mechanical properties of $Al_{85}-Ni_{8.5}-Mm_{6.5},\;Al_{84}-Ni_{8.5}-Mm_{6.5}Cu_1,\;Al_{84}-Ni_{8.5}-M_{m6.5}Fe_1$ alloys, manufactured by gas atomization, degassing and hot-extrusion were investigated. Gas atomization, with a wide super-cooled liquid region, allowed the alloy powders to exhibit varying microstructure depending primarily on the powder size and composition. Al hotextruded alloys consisted of homogeneously-distributed fine-grained fcc-Al matrix and intermetallic compounds. A substitution of 1 at.% Al by Cu increased the thermal stability of the amorphous phase and produced alloy microstructure with smaller fcc-Al grains. On the other hand, the same substitution of 1 at.% Al by Fe decreased the stability of the amorphous phase and produced larger fcc-Al grains. The formation of intermetallic compounds such as $Al_3Ni,\;Al_{11}Ce_3\;and\;Al_{11}La_3$ was suppressed by the addition of Cu or Fe. Among the three alloys examined, the highest Vickers hardness and compressive strength were obtained for $Al_{84}-Ni_{8.5}-M_{m6.5}Cu_1$ alloy, and related to the finest fcc-Al grain size attained from increased thermal stability with Cu addition.

사례분석에 의한 강구조 스타디움 레일 시스템 분류

김혜성,윤성원,Kim, Hye-Seong,Yoon, Sung-Won 한국공간구조학회 2010 한국공간구조학회지 Vol.10 No.1

국내에 설치될 강구조 스타디움에 향후 신재생에너지 중 하나인 태양광 발전을 위한 PV 시스템을 적용하는 것에 따른 강재 어레이에 관한 기초 연구로 해외의 사례를 토대로 구성되었다. 연구를 진행하기 위하여 1990년대 이후 PV 시스템이 적용된 강구조 스타디움 20건을 사례 분석 대상으로 선정하였다. 선정된 20건의 강구조 스타디움을 PV 모듈을 고정하기 위하여 설치된 레일 시스템에 따라 분류해 보았다. 그 결과 격자고정방식 중 선형모듈고정방식과 지붕 통합형이 전체의 28%에 해당되는 것으로 조사되었으며 그 뒤로 레일 고정형 17%, 세로 고정방식 중 모듈그룹 고정 11% 순으로 조사되었다. 또한 스타디움 내부에는 주로 격자 고정방식 중 선형모듈 고정방식과 지붕통합형이 적용되고 있었으며 스타디움 외부나 그 외 부분에서는 앵글 브라킷으로 PV 모듈이 고정되고 있는 것으로 조사되었다. This paper focuses on steel arrays regarding the application of PV system for solar power system, a renewable energy in steel structure stadium that will be built in Korea, by foreign case study. 20 cases of Steel Structure Stadiums applying PV system after 1990 were selected as the main subjects. The 20 cases of Steel Structure Stadiums were categorized by rail systems that were installed to fix PV module. As the result, linear clamping and roof-integrated type among cross rails were 28% of the whole, followed by 17% of rail-fixed type and 11% of module group-fixed type among vertical-fixed types. In addition, linear clamping and roof-integrated type among cross rails were applied in the inside of the stadium while the outside and other parts of stadiums used angle bracket to fix PV module.

기계적 합금화법에 의해 제조된 Al+Al3Ti합금 및 Al+10wt.%Ti합금의 고용현상

김혜성,이정일,김긍호,금동화,서동수( Hye Sung Kim,Jung Ill Lee,Gyeung Ho Kim,Dong Wha Kum,Dong Soo Shur ) 한국열처리공학회 1996 熱處理工學會誌 Vol.9 No.2

The solubility of Ti in Al matrix was determined by X-ray diffraction method on two different mechanical alloying systems, i.e Al+Al₃Ti and Al+Ti alloys. Starting powder compositions of two systems were chosen for final volume fraction of Al₃Ti phase being 25%. The solubility of Ti in α-Al was estimated by the lattice parameter measurement of Al. For Al+Al₃Ti mixture, it appeared that some of Al₃Ti particles decomposed during milling and maximum solubility of Ti in A1 was about 0.99%. The majority of Al₃Ti particles were dispersed uniformly in Al matrix, having approximate size of 100∼200㎚. On the other hand, higher Ti solubility of 1.24 wt.% was found in Al+Ti system, with starting composition of Al+10 wt.%Ti. After 15 hours of milling, Ti phase was identified as 20㎚ sized particles embedded in Al matrix. The annealing of mechanically alloyed powders from Al+Al₃Ti and Al+10 wt.%Ti systems was followed in the temperature range of 200 to 600℃ to study thermal stability of supersaturated solution of Al(Ti). After annealing, the lattice parameter of A1 reverted back to that of pure Al, and the peak intensity ratio of Al₃Ti/Al was increased more than the original value before annealing. These results suggest that Ti dissolve into alpha-Al solutions during milling, and by annealing, Do_(22)-Al₃Ti phase forms from Al(Ti) solution.

기계적 합금화 시료에서 미소상 피이크의 소멸현상 해석(Ⅱ)

김혜성(Hye-Sung Kim) 한국산업융합학회 2001 한국산업융합학회 논문집 Vol.4 No.1

Refining of powder particles and their dissolution into the Al matrix during mechanical alloying(MA) were investigated by using X-ray diffraction(XRD) transmission electron microscopy (TEM) functions of alloy composition, milling time and ball to powder ratio(BPR). It is found that Ti particles less than 20nm are observed in a dark field image of mechanically alloyed about 1wt%Ti whose XHD pattern exhibits no Ti peak. The observed change of lattice constant of AI indicates that about 1 wt%Ti can he solved in Al after MA for a long time, independent of alloy composition, milling time and BPR, suggesting that most of Ti particles arc retained in the Al matrix. It is concluded that the disappearance of XRD peaks in mechanically alloyed Al-10wt%Ti is not simply attributable to the dissolution of Ti into Al, but associated mainly with extreme refining and/or heavy straining of Ti Particles<br/> <br/>

3D 애니메이션 캐릭터의 조형성 연구

김혜성(Kim, Hye Sung),성례아(Sung, Re-A) 한국만화애니메이션학회 2014 만화애니메이션연구 Vol.- No.36

애니메이션은 미래의 영상시대에 한 축을 장식하고 대중문화를 선도할 것을 예견할 수 있다. 현재 많은 연구가 이루어지고 있는데 주로 문화산업으로서의 가치에 초점을 두거나, 애니메이션 제작기술과 방식에 관한 연구이다. 물론 애니메이션 캐릭터에 대한 연구도 끊임없이 나오고 있다. 본 연구는 3D 애니메이션 캐릭터의 ‘조형성’에 중점을 두었으며, 원론적인 이론에서 새로운 논리를 이끌어내어 차별화를 시도하였다. 이론적인 바탕으로만 해석되었던 캐릭터 연구에서 벗어나, 실질적으로 애니메이션을 보고, 느끼고 소비하는 관객의 입장에서 어떻게 인지되는지 파악하고 문제점들을 점검하고 나아갈 방향을 모색하고자 한다. 특히 예술적 가치와 상업적 성공을 이루어낸 애니메이션인 <겨울왕국(Frozen)>에 등장하는 캐릭터를 통하여 3D 애니메이션 캐릭터의 조형적 특성을 알아보고자 하였다. 이를 위해 문헌연구를 비롯하여 다양한 설문 조사와 델파이 분석을 시행하였다. 또한, 전문가들과 심도 깊은 논의를 통하여 조형성을 평가하기 위한 분석틀을 만들었으며, 이는 조형의 구성요소, 구성원리 및 시각인지요소 등의 형식을 구성하여 관객들이 3D 캐릭터를 어떻게 인지하는지 알아보았다. 이미지의 인지 과정은 사회?문화적 환경과 성, 나이, 지식수준 등에 따라 미치는 영향이 다르기 때문에 시각적 양식을 대표하는 <겨울왕국>의 캐릭터를 통하여 현재의 영상문화와 관객의 시각을 연구하였다. We can anticipate that animations will form one of the axes and lead popular culture in our future visual age. Recently, research has been actively conducted, but it mainly focuses on their value in culture industry or technologies and methods of producing animations. Of course, research that deals with animation characters has constantly come out. This study focuses on the ‘formative elements’ of 3D animation characters and attempts differentiation from other research by inducing new logic theoretically. Being freed from the research on characters that has been merely focused on theoretical grounds, this study intends to figure out how audience that is consumers who actually get to watch and feel animations recognizes them and find out related problems and also solutions for them. In particular, this study intends to examine the formative characteristics of 3D animation characters with the characters appearing in 〈Frozen〉, one of the animations that have achieved artistic value as well as commercial success. And for that, the study conducted not only literature review but various surveys and Delphi method as well. Also, the researcher devised an analysis frame to evaluate the formative elements through in-depth discussion with experts. And with this, the study created the forms such as the Elements of Form, Formation Methods of Form and Visual Recognition Elements of Form, examined how audience recognized 3D characters. The process of recognizing an image is influenced by socio-cultural environment or sex, age, and the level of knowledge differently. This was meant to investigate current visual culture and the public’s perspective through characters in 〈Frozen〉 that represent the visual mode.

수렴성 빔 전자회절 도형을 이용한 Al-Ti 합금의 상 분석

김혜성(Hye-Sung Kim) 한국산업융합학회 2001 한국산업융합학회 논문집 Vol.4 No.2

The use of primitive cell volume and zero order Laue (ZOLZ) pattern is proposed to identify phase in a complex microstructure. Single convergent beam electron pattern containing higher order Laue zone ring from a nanosized region is sufficient to calculate the primitive cell volume of the phase, while ZOLZ pattern is used to determine the zone axis of the crystal. A computer program is used to screen out possible phases from the value of measured cell volume from convergent beam electron diffraction (CBED) pattern. Indexing of ZOLZ pattern follows in the program to find the zone axis of the identification from a single CBED pattern. An example of the analysis is given from the rapidly solidified AI-Al₃Ti system.<br/> <br/> <br/>

가계 소득수준과 치과의료서비스 지출 경향

김혜성 ( Hye Sung Kim ),안은숙 ( Eun Suk Ahn ),김민영 ( Min Young Kim ),김선미 ( Sun Mi Kim ),신호성 ( Ho Sung Shin ) 대한구강보건학회 2014 大韓口腔保健學會誌 Vol.38 No.1

Objectives: This empirical study aimed to identify the differences in expenditures by household income level, as well as the patterns of dental care spending by dental services. Methods: We analyzed the Korea Health Panel`s data collected between 2008 and 2010. We calculated expenditures by service items by itemizing dental care services such as conservative, prosthetic, orthodontic, periodontal, surgical, preventive, dental implant care. Then we obtained the ratios of spending per item and per visit to overall out-of-pocket spending on dental care and used these as the weights for dental care cost allocation. Income quintiles were derived using the equivalence scale. Kakwani`s concentration index was used to determine the degree of disparity by income quintile, and 95%confidence intervals were computed. Results: Out-of-pocket expenditures on dental care steadily increased over time and income quintile. The analysis of dental care spending by income quintile revealed that the level of expenditure of the first income quintile was 3.6 times lower than that of the fifth income quintile. In terms of expenditure comparison between 2008 and 2010, the first quintile households showed an increased spending on prosthetic and periodontal treatments, whereas the fifth quintile households spent a relatively high proportion on orthodontic and dental implant care. The concentration index revealed that conservative services and root canal treatments was significant and positive, indicating that the demand for, and utilization of, these services increase as household income increases. In contrast, prosthetic services showed a significant negative trend, indicating that these services are not as common among those with higher incomes. Conclusions: To address the problems associated with the disparity in dental care expenditures based on income levels, it is necessary to establish policies that expand health insurance coverage and provide other supportive measures for low-income populations.

CD 로 복각된 유성기 음반 해제 및 목록

김혜성(Hye Sung Kim) 한국고음반연구회 2001 한국음반학 Vol.- No.11

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군 간호요원의 직무만족도에 관한 연구

김혜성 ( Hye Sung Kim ),이경희 ( Kyong Hee Lee ) 국군간호사관학교 군진간호연구소 1990 군진간호연구 Vol.10 No.-