중유전율 LTCC 기판용 $CaZrO_3-CaTiO_3$계 세라믹스의 저온소결 및 유전특성

박정현,최영진,고원준,박재환,박재관,Park Jeong-Hyun,Choi Young-Jin,Ko Won-Jun,Park Jae-Hwan,Park Jae-Gwan 한국마이크로전자및패키징학회 2004 마이크로전자 및 패키징학회지 Vol.11 No.3

[ $CaZrO_3$ ]세라믹스에 대하여 $CaTiO_3$세라믹스의 첨가량 변동에 따른 마이크로파 유전특성을 조사하였다. 또한 중유전율 LTCC 기능성 기판으로 활용하기 위하여 저융점의 유리 프리트를 첨가하여 $CaZrO_3-CaTiO_3$ 세라믹스의 저온 소결 거동과 마이크로파 유전특성을 평가하였다. 저온 소결 조제로 사용된 저응점의 유리 프리트를 $10-20 wt\%$ 범위로 첨가함으로서 $CaZrO_3-CaTiO_3$ 세라믹스의 소결온도를 $1450^{\circ}C$에서 $900^{\circ}C$이하로 낮출 수 있었다. 음의 온도계수를 갖는 $CaZrO_3$ 및 유리프리트에 대하여 양의 온도계수를 갖는 $CaTiO_3$ 세라믹스의 분율을 적정히 제어함으로서 제로의 온도계수를 구현할 수 있었다. $CaZrO_3-CaTiO_3$ 세라믹스에 저온 소결용 유리 프리트를 $15 wt\%$ 첨가하여 $875^{\circ}C$에서 소결한 경우. 유전율(k) 23, 품질계수(Q${\times}$f) 2500, 공진 주파수 온도계수$(T_f) -3 ppm/^{\circ}C$의 매우 양호한 마이크로파 유전특성을 나타내었다. The microwave dielectric properties of $CaZrO_3$ ceramics with addition of $CaTiO_3$ were studied. The effect of glass addition on the low-temperature sintering and microwave dielectric properties of $CaZrO_3-CaTiO_3$ ceramics were also evaluated to develop the materials for functional substrates of low-temperature co-fired ceramics. When $10-20 wt\%$ of lithium borosilicate glass was added, the sintering temperature of the $CaZrO_3-CaTiO_3$ ceramics decreased from $1450^{\circ}C$ to below $900^{\circ}C$. As the $T_f$ of glass frits and $CaZrO_3$ are slightly negative and that of $CaTiO_3$ is significantly positive, zero $T_f$ could be realized by mixing an appropriate amount of $CaTiO_3$ with $CaZrO_3$. The $CaZrO_3-CaTiO_3$ ceramics sintered at $875^{\circ}C$ with $15wt\%$ glass frits showed the relative density of $98\%$, permittivity of 23, quality factor of 2500 GHz, and temperature coefficient of resonant frequency of $ -3 ppm/^{\circ}C$.

LTCC 내장 캐패시터용 BaTiO₃계 세라믹스의 저온소결 및 유전특성

박정현,최영진,고원준,박재환,남산,박재관,Park, Jeong-Hyun,Choi, Young-Jin,Ko, Won-Jun,Park, Jae-Hwan,Nahm, Sahn,Park, Jae-Gwan 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.2

[ $BaTiO_3$ ]계 유전체 모재료에 대하여 $Al_{2}O_{3}$와 CaO 조성이 소량 포함된 lithium-borosilicate계 유리 프릿을 $5\~15wt\%$ 적용함으로써 LTCC용 내장 캐패시터로 적용 가능한 조성을 개발하였다. 이를 위하여 먼저, 화학적으로 안정하고 저온소성효과가 탁월한 유리 프릿 조성물을 설계하고 이를 유전체 모재료에 적용하여 저온소성특성 및 유전특성을 평가하였다. $BaTiO_3$ 세라믹스를 모재료로 하는 경우 유리 프릿을 5wt$\%$ 첨가하였을 때 $925^{\circ}C$에서 $95\%$ 정도의 상대밀도 값을 나타내었으며, 이 경우 유전율 990, 유전손실 $3.1\%$의 유전특성을 나타내었다. $(Ba,Ca)(Ti,Zr)O_3$ 세라믹스를 모재료로 하여 유리프릿을 10 wt$\%$ 첨가한 경우는 $875^{\circ}C$의 소결온도에서 상대밀도가 $95\%$ 이상이며 기공율 $0.5\%$ 이하인 소결특성을 나타내었고, 700 이상의 유전율 및 $2\%$ 내외의 유전손실 값을 가지는 것으로 측정되었다. The compositions for LTCC embedded capacitors based on $BaTiO_3$ ceramics with $5\~15\;wt\%$ of lithium-borosilicate glass frits were studied. After the glass frits, which is chemically stable and has acceptable ability of low-temperature sintering, were added to the host dielectric materials, the sintering behavior and dielectric properties were evaluated. As for $BaTiO_3$, relative density of >$95\%$, permittivity 990, and dielectric loss $3.1\%$ were obtained when sintered at $925^{\circ}C$ with 5 wt$\%$ of glass frits. As for $(Ba,Ca)(Ti,Zr)O_3$ ceramics, relative density of >$95\%$, open porosity <$0.5\%$, permittivity 700, and dielectric loss $2\%$ were obtained when sintered at $875^{\circ}C$ with 10 wt$\%$ of glass frits.

노년 여성을 위한 낙상충격 보호팬츠의 착의평가

박정현,이정란,Park, Jung Hyun,Lee, Jeong Ran 한국의류학회 2017 한국의류학회지 Vol.41 No.4

This study conducted a wearing evaluation of fall impact protective clothing developed in the previous study that evaluated activity, appearance, and practicality for elderly women. A total of 6 kinds of pants, which consisted of the three kinds of pads and two kinds of designs, were evaluated and the results are as follows. First, the activity of the protective clothing was tested with six women in their 60's and scored highly in most criterions that indicated satisfactory activity. The honeycomb type pad was superior in four of ten criterions for the activity evaluation results by pad types. Design B without a knee pad was evaluated as more comfortable on two motions that put pressure on the knee area. Second, the expert group considered design A to be better than design B, while the subject group preferred design B over design A in design appearance evaluation. Both the subject group and expert group evaluated that design A is better than design B in consideration of pads. Third, in the assessment of practicability, both the expert group and the subject group provided the highest score on the question of if elderly women needed protective clothing. The evaluation of washing ability indicated no noticeable change in the clothing form and size before and after washing.

만프레도 타푸리의 이데올로기 비판 독해를 위한 이중의 문맥

박정현,Park, Junghyun 한국건축역사학회 2016 건축역사연구 Vol.25 No.2

Autonomia movement that emerged in Italy in the 1960s from workerist (operaismo) communism gives historical and discursive context to Manfredo Tafuri's famous criticism of ideology. His thesis on the death of architecture was a radical criticism of Keynesian intervention which was a strategy to cope with the Great Depression. For him, this capitalist development had taken away ideological prefiguration from architecture. At least Tafuri's this early intellectual phase was formed in the wake of magazine Contrapiano and Antonio Negri's influence. Tafuri almost entirely adapted Negri's thought on the importance of capitalist innovation that was uncovered by Keynes, Schumpeter, and Manheim and the periodization in modern history. When we read Tafuri's text with this concrete context, we can avoid being plunged into his abstruseness. On the other hand, 1980's Korea cannot understand Tafuri comprehensibly. 1980's situation to struggle to acquire democracy prescribed only one mode of reception of Tafuri's historiography in Korea. Tafuri's so-called pessimist view point could not satisfy student activists. They want to take intellectual means to sustain student movement and to secure political dynamics of protest. But at the same time they have anxiety to understand tafuri's thesis that they consider ad a critical theory for Korean Architecture. Double contexts of Tafuri's criticism of ideology bring to light to historicize both Tafuri's historiography itself and reception of his text in Korea.

치과용 임플란트 적용 비귀금속 코어와 관련된 전조골세포의 변화

박정현,강신영,김종우,김장주,김웅철,김지환,Park, Jung-Hyun,Kang, Seen-Young,Kim, Jong-Woo,Kim, Jang-Ju,Kim, Woong-Chul,Kim, Ji-Hwan 대한치과기공학회 2018 대한치과기공학회지 Vol.40 No.2

Purpose: The purpose of this study is to investigate the non-precious metal core materials used in the dental laboratory to fabricate the implant superstructure by CAD / CAM method. And to observe and compare the morphology and distribution of the osteoblasts in relation to implant osseointegration. Methods: In this study, the mandibular right first molar tooth model was selected as an international standard to produce a single core. Using this model, the impression was made with the silicone rubber, the tooth model was scanned, and a single core was designed and 5-axis milling was performed. The materials used were Cobalt-Chromium and Nickel-Chromium, and the cores for dental implant top structures were fabricated according to the procedures of the dental labs. After the fabrication, the marginal area of the core was separated and cell culture experiment was performed. The osteoblast cells used MC3T3-E1, which is currently widely used. For morphological analysis of osteoblasts, cells were posttreated and observed using CLSM (Confocal Laser Scanning Microscope) and compared. Results: The cell adhesion behavior of the specimen surface measured by CLSM was uniformly distributed in specimen A (Cobalt-Chromium) than in specimen B (Nickel-Chromium). The distribution and changes of the cells were different in the two specimens. Conclusion : It is possible to confirm that specimen A (Cobalt-Chromium) is suitable for the living body through adhesion and proliferation of osteoblasts related to implant osseointegration in the non-precious metal superstructure used after implantation. It is considered that it is preferable to use Co-Cr when fabricating the superstructure.

PSZ, Al₂O₃, TiO₂를 반응소결하여 제조한 쾌삭(快削) 세라믹스

박정현,정동식,이원재,김일수,Park, Jeong Hyun,Jung, Dong Sik,Lee, Won Jae,Kim, Il Soo 한국세라믹학회 2012 한국세라믹학회지 Vol.49 No.6

Machinability is important in engineering applications, especially in the current micro-electronics industry. Most ceramic components have complex shapes and hence require machining generally with diamond tools, which incurs a high production cost. Recently, h-BN-containing machinable ceramics have been developed, but these materials are very expensive due to the high raw materials and production costs. Therefore, the development of low-cost machinable ceramics is necessary. In this study, inexpensive $Al_2TiO_5$ was studied as a replacement for h-BN. $Al_2O_3$, $TiO_2$ and partially stabilized $ZrO_2$(PSZ) powders were mixed with various mole ratios and were sintered at $1500^{\circ}C$ for 1 h. The density, hardness and strength were then measured. The phase analysis and microstructures were observed by XRD and SEM, respectively. The machinability of each specimen was tested by micro-hole machining. The results of this research showed that the produced composites could be used as low-cost machinable ceramics.

독립기념관의 건립과정과 담론 변화에 관한 연구

박정현,Park, Junghyun 한국건축역사학회 2016 건축역사연구 Vol.25 No.6

A discourse on the Independence Hall of Korea, a representative cultural project of the 1980s, has been understood as a repetition of the traditional debate of the 1960s. It was considered as a petrified propaganda aimed at ensuring the fragile legitimacy of the military regime, and the architect as a sympathizer. Even if all these facts are true, it does not give any explanation for the architecture. Scrutinizing the building process and the change of discourse in the Independence Hall of Korea, this paper tries to explore a section of contemporary Korean architecture in the 1980s. The architect who designed the Independence Hall of Korea is Kim Kiwoong, however, it was Kim Won who took charge of overall scheme for it. Kim Won replaced the role of a technocrat in the 1960s, who deprived architects of his autonomy. Against this backdrop, Kim Kiwoong attempted to explain his own building via various concept like postmodernism, which gave him very proper context. But, later, he appropriated words like void and madang. These derived from some architectural historian's researches in 1970s, and were to predict the architecture of the 1990s.

SW 개발 R&D 프로젝트에서 소스 코드 품질을 위한 정적분석

박정현,박영식,정효택,Park, J.H.,Park, Y.S.,Jung, H.T. 한국전자통신연구원 2017 전자통신동향분석 Vol.32 No.1

본고에서는 SW 개발 R&D 프로젝트에 개발 소스 품질 검증을 위한 정적분석 실행방안을 기술한다. 정적분석 실행 방안으로 소스 코드 품질 검증 대상 SW 개발 R&D 프로젝트 범위와 정적분석 검증 기준을 기술하고, 정적분석 검증을 위한 구체적 실행 방안과 검증 프로세스 그리고 정적분석 검증을 지원 환경 체계를 제시했다. 또 제시된 정적분석 검증 실행 방안에 근간하여 수행 중인 프로젝트에서 개발한 소스 코드에 대해 시범적으로 정적분석 검증을 수행하고 이를 바탕으로 정적분석 검증 실행의 안정적인 도입 및 운영 방향을 시사점으로 기술하였다. 제시된 정적분석 검증 실행 방안은 SW 개발 R&D 프로젝트에서 개발 소스 코드 품질 관리 및 유지를 위한 방안으로 고려해 볼 수 있을 것으로 기대한다.

Q-mark 모델의 R&D 품질 영향 분석

박정현,Park, J.H. 한국전자통신연구원 2015 전자통신동향분석 Vol.30 No.1

본고에서는 Q-mark 모델의 R&D(Research & Development) 품질 영향 분석을 기술한다. 이를 위해 Q-mark 모델 특징과 종류 그리고 절차를 간략히 기술하고, R&D 품질에 대한 Q-mark 인증 모델 영향에 대해 연구현장 설문조사 내용을 바탕으로 연구결과 완성도 측면, 대외 신뢰도 개선을 통한 과제 수주 측면, 기술 이전과 사업화 측면, 그리고 과제관리 효율화 측면 등에서 분석하여 제시한다. 또 앞으로 Q-mark 모델이 보다 객관적이고 효과적인 R&D 품질관리를 위한 인증 모델로 개선되고 지속적으로 운영되기 위해 보완되어야 할 사항에 대해 설문조사 결과를 바탕으로 인증 측면, 프로세스 범주 측면, 제공 템플릿 측면, 그리고 품질 지원 서비스 및 전문성 측면에서 기술한다.

백서(白鼠)의 B16-F10 Melanoma에 대한 한련초약침(旱蓮草藥鍼)의 항암(抗癌) 및 면역증강효과(免疫增强效果)

박정현,김영일,홍권의,임윤경,이현,이병렬,Park, Jung-hyeun,Kim, Young-il,Hong, Kwon-eui,Yim, Yun-kyoung,Lee, Hyun,Lee, Byung-ryul 대한침구의학회 2004 대한침구의학회지 Vol.21 No.6

Objective & Methods : To study the effects of anti-cancer, anti-metastasis and immune response improvement of herbal-acupuncture with Eclipta prostrata diffusae herba infusion solution(ELP-HAS), we injected ELP-HAS into Chung-wan(CV12) of C57BL/6 mice implanted intravenously with B16-F10 melanoma. We have reached the following conclusion through the effect on the percentage of $CD25^+/CD4^+$, $CD8^+/CD3e^+$, $CD69^+/B220^+$, $NK1.1^+/CD3e^+$cells in mouse PBMCs, the effect on the pulmonary colony formation number, and the effect on MST(Median Survival Time) and ILS(Increase of Life Span) of C57BL/6 mice implanted intravenously with B16-F10 melanoma. Results : The results were obtained as follows : 1. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, the spleen cell proliferation in BALB/c mouse was significantly increased compared with control group. 2. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, the percentage of $CD25^+/CD4^+$, $CD8^+/CD3e^+$, $CD69^+/B220^+$, $NK1.1^+/CD3e^+$cells in C57BL/6 mouse PBMCs was increased compared with control group. 3. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, the pulmonary colony formation number of C57BL/6 mice implanted intravenously with B16-F10 melanoma was decreased significantly compared with control group. 4. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, MST(Median Survival Time) and ILS(Increase of Life Span) of C57BL/6 mice implanted intravenously with B16-F10 melanoma were increased significantly compared with control group. Conclusions : ELP Herbal acupuncture injection into Chung-wan(CV12) of C57BL/6 mice is considered to be effective in anti-cancer, anti-metastasis and immune response improvement.