스폰지 복제법을 이용한 Ag 코팅 BCP 지지체의 제조 및 평가

김민성,김영희,송호연,민영기,이병택,Kim, Min-Sung,Kim, Young-Hee,Song, Ho-Yeon,Min, Young-Ki,Lee, Byong-Taek 한국재료학회 2010 한국재료학회지 Vol.20 No.8

As a starting material, BCP (biphasic calcium phosphate) nano powder was synthesized by a hydrothermal microwave-assisted process. A highly porous BCP scaffold was fabricated by the sponge replica method using 60 ppi (pore per inch) of polyurethane sponge. The BCP scaffold had interconnected pores ranging from $100\;{\mu}m$ to $1000\;{\mu}m$, which were similar to natural cancellous bone. To realize the antibacterial property, a microwave-assisted nano Ag spot coating process was used. The morphology and distribution of nano Ag particles were different depending on the coating conditions, such as concentration of the $AgNO_3$ solution, microwave irradiation times, etc. With an increased microwave irradiation time, the amount of coated nano Ag particles increased. The surface of the BCP scaffold was totally covered with nano Ag particles homogeneously at 20 seconds of microwave irradiation time when 0.6 g of $AgNO_3$ was used. With an increased amount of $AgNO_3$ and irradiation time, the size of the coated particles increased. Antibacterial activities of the solution extracted from the Ag-coated BCP scaffold were examined against gram-negative (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus). When 0.6 g of $AgNO_3$ was used for coating the Ag-coated scaffold, it showed higher antibacterial activities than that of the Ag-coated scaffold using 0.8 g of $AgNO_3$.

한국어 연속 숫자음 전화 음성 인식에서의 오인식 유형 분석

김민성,정성윤,손종목,배건성,김상훈,Kim Min Sung,Jung Sung Yun,Son Jong Mok,Bae Keun Sung,Kim Sang Hun 대한음성학회 2003 말소리 Vol.46 No.-

Channel distortion and coarticulation effect in the Korean connected digit telephone speech make it difficult to achieve high performance of connected digit recognition in the telephone environment. In this paper, as a basic research to improve the recognition performance of Korean connected digit telephone speech, recognition error patterns are investigated and analyzed. Korean connected digit telephone speech database released by SiTEC and HTK system are used for recognition experiments. Both DWFBA and MRTCN methods are used for feature extraction and channel compensation, respectively. Experimental results are discussed with our findings.

채널보상기법을 사용한 전화 음성 연속숫자음의 인식 성능향상

김민성,정성윤,손종목,배건성,Kim Min Sung,Jung Sung Yun,Son Jong Mok,Bae Keun Sung 대한음성학회 2002 말소리 Vol.44 No.-

Channel distortion degrades the performance of speech recognizer in telephone environment. It mainly results from the bandwidth limitation and variation of transmission channel. Variation of channel characteristics is usually represented as baseline shift in the cepstrum domain. Thus undesirable effect of the channel variation can be removed by subtracting the mean from the cepstrum. In this paper, to improve the recognition performance of Korea connected digit telephone speech, channel compensation methods such as CMN (Cepstral Mean Normalization), RTCN (Real Time Cepatral Normalization), MCMN (Modified CMN) and MRTCN (Modified RTCN) are applied to the static MFCC. Both MCMN and MRTCN are obtained from the CMN and RTCN, respectively, using variance normalization in the cepstrum domain. Using HTK v3.1 system, recognition experiments are performed for Korean connected digit telephone speech database released by SITEC (Speech Information Technology & Industry Promotion Center). Experiments have shown that MRTCN gives the best result with recognition rate of 90.11% for connected digit. This corresponds to the performance improvement over MFCC alone by 1.72%, i.e, error reduction rate of 14.82%.

열린타원구멍을 통한 기이색전증이 발병 원인으로 추정되는 뇌경색 환자의 동서 협진 치험 1례

김민성,옥효준,양지연,정택수,선종주,유소정,Kim, Min-sung,Ok, Hyo-joon,Yang, Jee-yun,Jeong, Taek-su,Sun, Jong-joo,You, So-jung 대한한방내과학회 2016 大韓韓方內科學會誌 Vol.37 No.5

Objective: To evaluate the effects of integrative treatment with conventional and Korean medicine on cerebral infarction due to presumed paradoxical embolism through a patent foramen ovale. Methods: We applied acupuncture, herbal medication, western medication, and physical therapy routinely every day and applied fluid therapy provided as needed. The NIHSS, K-MBI, MRS, MMT, and MMSE-K score were determined to assess any improvement in symptoms. Results: Scores appeared to be improved for the NIHSS (9 to 5), K-MBI (94 to 100), MRS (2 to 1), MMT (2+, 4 to 4, 4), MMSE-K (24 to 26). No side effects were observed during the treatment. Conclusions: This study demonstrates that integrative treatment with conventional and Korean medicine may be an effective option for treating cerebral infarction due to a presumed paradoxical embolism through a patent foramen ovale.

참옻 추출물의 MCF-7 인체 유방암 세포에서 증식 억제효과

김민성,안원근,이장천,Kim, Min Sung,An, Won Gun,Lee, Jang Cheon 대한한의학방제학회 2016 大韓韓醫學方劑學會誌 Vol.24 No.4

Objectives : The purpose of this study was to investigate the anti-cancer effects of extract of Rhus verniciflua Stokes (RVS) in human breast cancer cell lines. Methods : In cultured human breast cancer MCF-7 cells, we investigated growth inhibitory effect of RVS. MCF-7 cells were cultured with various concentrations (0, 200, 300, and 400 ug/ml) of RVS at $37^{\circ}C$ for 24 h. We performed CCK-8 assay and flow cytometry for detection of Annexin V-PI staining. Results : As a result, RVS inhibits the cell growth and induction of apoptosis in dose dependent manner in MCF-7 breast cancer cells. Conclusion : RVS has anti-cancer activities and induced apoptosis in human breast cancer MCF-7 cells. Therefore we suggest that RVS can use as a novel class of anti-cancer drugs.

손모양 인식기반의 경로교사와 장애물 인식이 가능한 자율보행 다족로봇 시스템

김민성,정우원,권배근,강동중,Kim, Min-Sung,Jeong, Woo-Won,Kwan, Bae-Guen,Kang, Dong-Joong 한국정보통신학회 2010 한국정보통신학회논문지 Vol.14 No.8

영상카메라와 무선통신 기능을 탑재한 손모양 및 장애물 인식이 가능한 다족 로봇을 독자적으로 설계 및 제작하고 제작한 로봇에 최적화된 보행패턴 알고리즘을 개발하여 적용하였다. 영상센서의 입력화상에 대해 하프변환 (Hough Transform)을 사용하여 물체의 외곽선을 추출하여 장애물을 인식하여 회피하는 실시간 자율보행이 가능한 알고리즘을 개발하였다. 로봇의 목표물 및 목적지 설정을 위하여 미리 학습시킨 피부색의 평균값과 입력영상의 확률거리(Mahalanobis Distance)를 산출하여 손 영역을 검출하고 손가락 개수에 따라 로봇의 명령 제어가 가능하도록 하였다. 장애물 및 손모양 인식에 따른 다족 자율 보행 로봇의 수행 실험 평균 결과 약 96%의 장애물 인식률과 94%의 손 모양 인식률을 보였다. In this paper, multi-legged robot was designed and produced using stable walking pattern algorithm. The robot had embedded camera and wireless communication function and it is possible to recognize both hand posture and obstacles. The algorithm decided moving paths, and recognized and avoided obstacles through Hough Transform using Edge Detection of inputed image from image sensor. The robot can be controlled by hand posture using Mahalanobis Distance and average value of skin's color pixel, which is previously learned in order to decide the destination. The developed system has shown obstacle detection rate of 96% and hand posture recognition rate of 94%.

pH 나노센서로의 응용을 위한 UV-가교 P4VP 박막에 고정한 금 나노입자의 특성

김민성,정연태,Kim, Min-Sung,Jeong, Yeon-Tae 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.11

In this report, we describe the use of gold nanoparticles (AuNPs) immobilized on pH. responsive, cross-linked poly(4-vinylpyridine) (P4VP) thin films, as a potential application for pH nanosensors. The methodology is based on the variation in surface plasmon resonance of immobilized AuNPs with changing the interparticle distances, caused by the swelling/deswelling of the pH responsive P4VP polymer films. The change in optical properties of the immobilized AuNPs in response to the pH of surrounding media was investigated by a simple yet powerful tool; UV-vis absorption spectroscopy. The swelling of the P4VP chains at pH 2 causes an increase in the interparticle distances of immobilized AUNPS ($\sim20nm$) and hence leads to a blue shift of 48 nm in their surface plasmon resonance band peak. On the other hand, when the surrounding media was altered from pH 2 to 10, a red shift of absorption maxima was observed. The changes were rapid, and the effect was reversible. This system could prove to be useful in fabricating nanosensors for detecting the pH or pH changes of surrounding aqueous medium.

금속산화물 복합분말의 동결건조 및 수소분위기 환원처리에 의한 Cu-Sn 다공체 제조

김민성,유호석,오승탁,현창용,Kim, Min-Sung,Yoo, Ho-Suk,Oh, Sung-Tag,Hyun, Chang-Yong 한국재료학회 2013 한국재료학회지 Vol.23 No.12

Freeze drying of a porous Cu-Sn alloy with unidirectionally aligned pore channels was accomplished by using a composite powder of CuO-$SnO_2$ and camphene. Camphene slurries with CuO-$SnO_2$ content of 3, 5 and 10 vol% were prepared by mixing with a small amount of dispersant at $50^{\circ}C$. Freezing of a slurry was done at $-25^{\circ}C$ while the growth direction of the camphene was unidirectionally controlled. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green bodies were hydrogen-reduced at $650^{\circ}C$ and then were sintered at $650^{\circ}C$ and $750^{\circ}C$ for 1 h. XRD analysis revealed that the CuO-$SnO_2$ powder was completely converted to Cu-Sn alloy without any reaction phases. The sintered samples showed large pores with an average size of above $100{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal walls of the large pores had relatively small pores. The size of the large pores decreased with increasing CuO-$SnO_2$ content due to the change of the degree of powder rearrangement in the slurry. The size of the small pores decreased with increase of the sintering temperature from $650^{\circ}C$ to $750^{\circ}C$, while that of the large pores was unchanged. These results suggest that a porous alloy body with aligned large pores can be fabricated by a freeze-drying and hydrogen reduction process using oxide powders.

PMIC용 32bit eFuse OTP 설계

김민성,윤건수,장지혜,김려연,하판봉,김영희,Kim, Min-Sung,Yoon, Keon-Soo,Jang, Ji-Hye,Jin, Liyan,Ha, Pan-Bong,Kim, Young-Hee 한국정보통신학회 2011 한국정보통신학회논문지 Vol.15 No.10

본 논문에서는 Magnachip $0.18{\mu}m$ 공정을 이용하여 PMIC용 32bit eFuse OTP IP를 설계하였다. eFuse 링크 아래에 N-Well을 두어 프로그램시 eFuse 링크와 p-기판의 VSS가 단락되는 문제점을 해결하였다. 그리고 디코딩된 WERP (WL Enable for Read or Program) 신호가 eFuse OTP 메모리로 바로 입력되는 경우 듀얼 포트 eFuse OTP 메모리 셀의 RWL (Read Word-Line)과 WWL (Write Word-Line)을 선택적으로 활성화해 주는 WL 구동회로를 제안하였다. 또한 BL 프리차징 회로에서 delay chain을 제거하여 제어회로의 레이아웃 면적을 줄였다. 메모리 테스트 장비를 이용하여 제작된 94개의 샘플 die를 측정한 결과 5.5V의 프로그램 전압에서 100%의 수율을 얻었다. In this paper, we design a 32-bit eFuse OTP memory for PMICs using MagnaChip's $0.18{\mu}m$ process. We solve a problem of an electrical shortage between an eFuse link and the VSS of a p-substrate in programming by placing an n-well under the eFuse link. Also, we propose a WL driver circuit which activates the RWL (read word-line) or WWL (write word-line) of a dual-port eFuse OTP memory cell selectively when a decoded WERP (WL enable for read or program) signal is inputted to the eFuse OTP memory directly. Furthermore, we reduce the layout area of the control circuit by removing a delay chain in the BL precharging circuit. We'can obtain an yield of 100% at a program voltage of 5.5V on 94 manufactured sample dies when measured with memory tester equipment.

실험적 골 병소에 대한 콘빔형전산화단층영상과 초음파영상의 비교

김민성,박철우,김규태,최용석,황의환,Kim, Min-Sung,Park, Cheol-Woo,Kim, Gyu-Tae,Choi, Yong-Suk,Hwang, Eui-Hwan 대한영상치의학회 2010 Imaging Science in Dentistry Vol.40 No.3

Purpose : This study was performed to evaluate the diagnostic ability of ultrasonography in detection of bone defects and new bone formation. Materials and Methods : Experimental bony defects were prepared on the parietal bone samples acquired from 3.5 kg New Zealand male rabbits. The defects were evaluated using ultrasonography and CBCT, and examined histologically at interval of 1, 3, 6, and 8 weeks. Results : Ultrasonograph demonstrated hyperechogenicity in the defect area at 3 weeks and broadened hyperechogenicity from the margin of bone defect at 6 and 8 weeks due to new bone formation. On the CBCT images, new bone formation was first observed at 3 weeks around the margin of the defect, and showed gradually increase at 6 and 8 weeks. Histologic findings revealed existence of the fibroblasts and fibrous connective tissue with abundant capillary vessels only at 1 week, but osteoid tissue and newly formed trabecular bone at 3 weeks. Bone remodeling in the defect area was observed at 6 weeks and increased calcification and dense trabecular bone formation was observed at 8 weeks. Conclusions : Ultrasonograph proved to be a very useful diagnostic tool in detecting the bony defect and new bone formation. Additionally, ultrasonography provided valuable information regarding the blood supply around the defect area.