In-situ $MgB_2$ 선재의 소결온도와 SiC 함량에 따른 미세조직 및 초전도 특성 연구

황수민,박의철,박시홍,장석헌,김규태,임준형,주진호,강원남,김찬중,Hwang, Soo-Min,Park, Eui-Cheol,Park, Si-Hong,Jang, Seok-Hern,Kim, Kyu-Tae,Lim, Jun-Hyung,Joo, Jin-Ho,Kang, Won-Nam,Kim, Chan-Joong 한국초전도학회 2007 Progress in superconductivity Vol.9 No.1

We fabricated the in-situ $MgB_2$ wires using the powder-in-tube method and investigated the effects of sintering temperature and SiC contents on the microstructure and superconducting properties. Pure $MgB_2$ wires and 5, 10, 20 wt.% SiC doped $MgB_2$ wires were sintered at $600-1000^{\circ}C$ for 30 minutes in Ar atmosphere. We found that $MgB_2$ phase was mostly formed at the sintering temperature of $700^{\circ}C$ and above, and the critical temperature ($T_c$) increased with increasing sintering temperature. For the $MgB_2$ sintered at $850^{\circ}C$, the highest critical current density ($J_c$) was obtained to be $3.7{\times}10^5\;A/cm^2$ at 5 K and 1.6 T by a magnetic properties measurement system (MPMS). The addition of SiC to the $MgB_2$ wires changed microstructure and critical properties. SEM observation showed that the $MgB_2$ core had considerable micro-cracks in undoped wire and the density of micro-cracks decreased with increasing SiC contents. The critical temperature decreased as the SiC contents increased, on the other hand, the critical current density of SiC doped $MgB_2$ wires in high magnetic field was enhanced compared to that of undoped $MgB_2$ wires.

기계적 합금화 및 in-situ와 ex-situ의 혼합공정을 통한 C 도핑된 ex-situ $MgB_2$ 선재 제조

황수민,이창민,임준형,최준혁,박진현,주진호,전병혁,김찬중,Hwang, Soo-Min,Lee, Chang-Min,Lim, Jun-Hyung,Choi, Jun-Hyuk,Park, Jin-Hyun,Joo, Jin-Ho,Jun, Byung-Hyuk,Kim, Chan-Joong 한국초전도학회 2009 Progress in superconductivity Vol.10 No.2

We successfully fabricated C-doped ex-situ $MgB_2$ wires using two different methods such as mechanical alloying(MA) and combined process(CP) of in-situ and ex-situ. In the MA, the precursor powder was prepared with a mixture of $MgB_2$ and 1 at% C powders by planetary ball milling for 0-100 h. In the CP, on the other hand, C-doped $MgB_2$ powder was prepared with Mg, B, and C powders by in-situ process via compaction, sintering, and crushing. The powders prepared by two methods were loaded into Fe tube and then the assemblages were drawn by a conventional powder-in-tube technique. The MA treatment of C-added $MgB_2$ decreased the particles/grains size and resulted in C-doping into $MgB_2$ after sintering, improving the critical current density($J_c$) in high external magnetic field. For the C-doped $MgB_2$ wire by MA for 25 h, the $J_c$ was $4.1{\times}10^3A/cm^2$ at 5 K and 6.4 T, which was 5.9 times higher than that of pure and untreated $MgB_2$ wire. The CP also provided C-doping into $MgB_2$ and improved the $J_c$ in high magnetic field; the C-doped $MgB_2$ wire fabricated by CP exhibited a $J_c$ being 2.3 times higher than that of the ex-situ wire used commercial $MgB_2$ powder at 5 K and 6.0 T($2.7{\times}10^3A/cm^2\;vs.\;1.2{\times}10^3A/cm^2$).

자율자동차 Head Up Display 구성에 관한 연구

황수민(Su min Hwang),신혜진(Hye jin Shin),김선철(Sun Chul Kim) 경희대학교 산학협력단 예술디자인연구원 2015 예술· 디자인학연구 Vol.18 No.1

전열촉진관을 이용한 CFC12 대체 냉매의 응축열전달에 관한 연구

황수민(S.M. Hwang),조성준(S.J. Cho),정동수(D.S. Jung),김종보(J.B. Kim) 대한설비공학회 1998 대한설비공학회 학술발표대회논문집 Vol.1998 No.6-1

헤어아트 연구 동향 분석

황수민(Soo Min Hwang),김진숙(Jin Sook Kim) 한국인체미용예술학회 2017 한국인체미용예술학회지 Vol.18 No.3

Science technology has developed in modern society, and people’s literary level and aesthetic value standards have not only increased but also become more diverse. This trend has ushered in the advancement of popular culture and both pursues and forms integrated beauty in an interaction with art, culture, film and academic studies. The aesthetic pursuit of modern people has included the search for uniqueness and diversity. In addition, the development of a new genre called ‘hair art’ in the beauty arts offers a new possibility for artistic values. The creation of hair as art work is evolving into a new formative art and recently, hair art has emerged as a field of study with possibilities in the beauty arts. As a result, there have been studies on ‘hair art’ in some colleges. Even though diverse research methods and creative hair art studies have been conducted, however, the expression methods have been limited. In addition, there has been a need to make use of new motifs or other materials in setting the research topic. Therefore, this study attempted to investigate previous hair art-related studies and to suggest a future direction for hair art according to current trends. A total of 104 academic journals and papers on hair art from the National Assembly Library of Korea, RISS and KISS were analyzed and redundant studies were excluded from this survey.

VR 콘텐츠의 공간 오디오 상호작용 사례 연구

황수민 ( Hwang Sumin ),한정엽 ( Han Jungyeob ) 한국공간디자인학회 2020 한국공간디자인학회논문집 Vol.15 No.8

(연구배경 및 목적) 최근 5G 기술의 상용화로 몰입감과 실시간으로 체험 가능한 환경 구축에 따라 인간의 감각 기관을 통하여 정보와 경험을 제공하는 실감 콘텐츠가 주목 받고 있다. 이러한 경험을 위해서는 시각 경험 못지않게 청각 경험도 중요한데, 대부분의 연구는 시각 중심의 상호작용 방식에 머물러 있다. 따라서 본 연구는 VR 콘텐츠에서 공간 오디오의 상호작용 사례를 분석하여 기존에 시각 중심으로 이루어졌던 상호작용 방식을 벗어나 공간 음향을 이용한 새로운 상호작용 방식의 가능성과 방향성을 제안하는 데 목적이 있다. (연구방법) 문헌 고찰을 기반으로 노먼의 상호작용 사이클의 단계별 모형을 근거하여 VR 콘텐츠에서 공간 오디오를 통해 체험자와 상호작용하는 과정의 행위적 특성을 도출한다. (결과) 공간 오디오의 상호작용 사례들은 다음과 같은 특징을 가지고 있다. 첫째, 공간 오디오의 방향성 유형은 어떠한 사건에서 오브제가 세상에 처음 나오는 위치를 알리거나 체험자에게 스토리 전개의 위치를 알리기 위해 사용되는 것을 확인할 수 있었다. 둘째, 공간 오디오의 거리감 유형은 체험자와 오브제의 거리가 근접하는 것을 고지하는 방법으로 사용하거나 오디오와 체험자의 위치 변화에 따른 행동 유도의 방법으로 사용됨을 확인할 수 있다. 셋째, 공간 오디오의 예측성 유형은 가상현실에서 마찬가지로 오브제가 가진 소리만으로 대상을 예측 가능한 것을 확인하였다. 이 밖에도 오브제가 추상적인 형태를 지니고 있어도 소리를 통해 오브제의 유형을 예측함을 확인하였다. 넷째, 공간 오디오의 주목성 유형은 짧고 강한 소리는 단시간에 체험자의 시선을 유도했고, 콘텐츠와 어우러진 소리는 이야기 전개의 시작을 알리는 서사의 역할을 하였다. 다섯째, 공간 오디오의 커뮤니케이션 유형은 체험자는 이야기를 하는 캐릭터를 응시하거나 대화의 내용을 명확하게 듣기 위하여 가까이 다가가는 행동을 취하는 등 현실과 같은 대화가 가능하다. (결론) VR콘텐츠에서 공간 오디오는 상호작용 도구 개발에 있어 적합한 인터랙션 디자인의 중요한 요소임을 확인하였다. VR 콘텐츠는 실제와 유사한 감각 정보를 통해 체험자와 상호작용하는데, 평면 디스플레이에서 이루어졌던 기존 미디어의 상호작용 방식을 적용하는 데 한계가 있다. 본 연구를 통해 제시된 공간 오디오의 상호작용 특성은 향후 오디오 UI의 디자인 방향성에 기반이 되어 VR 콘텐츠에서 청각 경험의 활용을 기대해 본다. (Background and Purpose) There has been a heightened interest in realistic contents that provide information and experiences through human sensory organs amid the recent commercialization of 5G technology that enables creation of environment for immersive and real-time experiences. For such experiences, auditory experience, as well as visual experience, is important, and most of the studies thus far have focused on the modes of visual-centered interactions. Thus, the purpose of this study was to analyze actual cases of spatial audio interaction in VR contents so as to propose the possibility and courses for novel modes of interaction made by using the spatial sound, shifting away from conventional modes of visual-centered interaction. (Method) Based on literature review and Norman's model of interaction cycle by phase, we derived the behavioral characteristics of the process of interaction with user, experiencing the VR contents, through Spatial Audio in VR contents. (Results) The cases of Spatial Audio interaction showed the following characteristics. First, it was found that the directional type of Spatial Audio was used to indicate the location of the initial emergence of objets into the world from certain incident or to inform the user, experiencing the VR contents, of the position of storytelling. Second, it was found that the distance sense type of Spatial Audio was used as a method for alerting the user to the narrowing distance between the user himself/herself and the objets, or as a method for inducing certain behaviors according to the variation of the location of the audio and the user. Third, the predictability type of Spatial Audio was found to allow the objects to be predicted only with the sound that objets had in the same way as in virtual reality. Fourth, the attention type of Spatial Audio was short and the intensive led the user to avert the gaze of user instantly. Fifth, the communication type of Spatial Audio allowed the user, experiencing the virtual contents, to stare at the character telling the story or to be engaged in realistic conversation. (Conclusions) In VR contents, spatial audio was found to be an important element of suitable interaction design in developing the interactive tools. VR contents interact with participants who are using VR contents through sensory information similar to that of reality, but have limitation to their application of the existing modes of media interaction occurring on flat displays. This researcher hopes that the characteristics of spatial audio interaction, presented through this study, would help create a basis for designing the course for audio UIs in the period ahead and be utilized for auditory experience in VR contents.

톤 온 톤&톤 인 톤 배색기법을 적용한 헤어 디자인 작품 연구 : O.M.C 헤어 월드 종목 중심으로

황수민(Soo-Min Hwang) 한국인체미용예술학회 2021 한국인체미용예술학회지 Vol.22 No.4

In terms of the meaning of hairstyling competitions, the creativity and color of new hairstyle can be analyzed from the perspective of cosmetology industry. Through creative activities, then, it is possible to promote cosmetology culture according to the globalization of hair trends along with hair salon practices. One of the most popular and trending hairstyling competitions is Organization Mondiale de la Coiffure (O.M.C) HAIR WORLD. In hairstyling, color is crucial in determining the images of hairstyles. According to contemporary and annual trends, diverse color combinations have been used for hair coloring. In hairstyling competitions, color has a considerable influence on hairstyles and images and is important from a visual aspect. Therefore, this study investigated and analyzed the images of the hairstyles from the O.M.C HAIR WORLD from 2014 when Korean hairdressers started to participate and win the championship to 2018. Then, it suggested hairstyles and color matches, using tone-on-tone and tone-in-tone combinations which are most common coloring combinations. It is anticipated that the study results would be available as the data which are needed in analyzing hair collections and predicting color combination trends.

화포천내 유기화합물질에 대한 LC-HRMS 정량분석 및 위해성 평가

황수민(Sumin Hwang),전준호(Junho Jeon) 환경독성보건학회 2018 한국독성학회 심포지움 및 학술발표회 Vol.2018 No.6

$MgB_2$ bulk의 미세구조와 임계전류밀도에 미치는 polyacrylic acid doping 효과

이승묵,황수민,이창민,주진호,김찬중,Lee, S.M.,Hwang, S.M.,Lee, C.M.,Joo, J.,Kim, C.J. 한국초전도학회 2010 Progress in superconductivity Vol.11 No.2

We fabricated the polyacrylic acid (PAA)-doped $MgB_2$ bulks and characterized their lattice parameters, actual C substitutions, microstructures, and critical properties. The boron (B) powder was mixed with PAA using N,N-dimethylformamide as solvent and then the solution was dried out at $200^{\circ}C$ and crushed. The C treated B powder and magnesium powder were mixed and compacted by uniaxial pressing at 500 MPa, followed by sintering at $900^{\circ}C$ for 1 h in high purity Ar atmosphere. We observed that the PAA doping increased the MgO amount but decreased the grain size, a-axis lattice constant, and critical temperature ($T_c$), which is indicative of the C substitution for B sites in $MgB_2$. In addition, the critical current density ($J_c$) at high magnetic field was significantly improved with increasing PAA addition: at 5 K and 6.6 T, the $J_c$ of 7 wt% PAA-doped sample was $6.39\;{\times}\;10^3\;A/cm^2$ which was approximately 6-fold higher than that of the pure sample ($1.04\;{\times}\;10^3\;A/cm^2$). This improvement was probably due to the C substitution and the refinement of grain size by PAA doping, suggesting that PAA is an effective dopant in improving $J_c$(B) performance of $MgB_2$.

설부 종물로 나타난 어류골편이물 1예

주영호,황수민,박상헌,정광윤,Ju, Young Ho,Hwang, Soo Min,Park, Sangheon,Jung, Kwang-Yoon 대한기관식도과학회 2013 大韓氣管食道科學會誌 Vol.19 No.1

Foreign bodies in the oral cavity and pharyngolarynx are frequently observed accidental cases in the otolaryngological fields. Most foreign bodies can be recognized and removable with the manipulation of endoscopes and various instruments. However, foreign bodies that penetrate the oral cavity and oropharynx to appear as a tongue mass are rare. Therefore, such cases easily can be misconceived as tongue tumor at first, so it must involve a more thorough search utilizing such aids as computed tomography. Depending on their location and size, their removal may involve surgical intervention. The authors experienced such a rare case of an elderly male patient, presenting as tongue mass. We hereby report this case along with the relevant literature.