소결온도 및 SiO₂ 첨가량에 따른 탄화규소의 마모 특성

박성호,박원조,윤한기,Park, Sung-Ho,Park, Won-Jo,Yoon, Han-Ki 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.11

In this study, liquid phase sintered SiC (LPS-SiC) materials were made by hot pressing method. The particle size of nano-SiC powder was 30nm. Alumina ($Al_2O_3$), yttria ($Y_2O_3$) and silica ($SiO_2$) were used for sintering additives. To investigate effects of $SiO_2$, ratios of $SiO_2$ contents were changed by five kinds. Materials have been sintered for 1 hour at $1760^{\circ}C$, $1780^{\circ}C$ and $1800^{\circ}C$ under the pressure of 20MPa. The system of sintering additives which affects a property of sintering as well as the influence depending on compositions of sintering additives were investigated by measurement of density, mechanical properties such as flexural strength, vickers hardness and sliding wear resistance were investigated to make sure of the optimum condition which is about matrix of $SiC_f$/SiC composites. The abrasion test condition apply to load of 20N at 100RPM for 20min. Sintered density, flexural strength of fabricated LPS-SiC increased with increasing the sintering temperature. And in case of LPS-SiC with low $SiO_2$, sliding wear resistance has very excellent. Monolithic SiC $1800^{\circ}C$ sintering temperatures and 3wt% have excellent wear resistance.

Etch Rate Dependence of Differently Doped Poly-Si Films on the Plasma Parameters

박성호,김윤태,김진섭,김보우,마동성,Park, Sung-Ho,Kim, Youn-Tae,Kim, Jin-Sup,Kim, Bo-Woo,Ma, Dong-Sung 대한전자공학회 1988 전자공학회논문지 Vol. No.

플리즈마 변수로서 가스조성과 압력 및 RF 전력이 인 및 붕소가 각각 다른 양으로 주입된 다결정 실리콘의 식각율 변화에 미치는 영향을 고찰하였다. $POCl_3$에 의해 인이 주입된 경우, 염소조성보다 불소조성이 많은 영역, 즉 $Cl_2$와 $SF_4$의 비가 17대 33일 때, 가장 큰 비등방성과 가장 작은 선폭손실을 달성하였다. 플라즈마 조건에 관계없이 주입된 불순물 농도의 증가에 다라, 인이 주입된 경우는 식각율이 증가하였고, 붕소가 주입된 경우는 식각율이 반대로 감소하였다. 또한, 급속 열처리에 의한 활성화 시간의 함수로서 인이 주입된 다결정실리콘의 식각율변화를 측정한 결과, 도우핑 농도뿐 아니라 활성화된 운반자, 즉 전자의 농도가 그 식각율 증가에 중요한 역할을 한다는 것을 확인하였다. The dependence of the etch rates of differently doped poly-Si films on the gas composition, the chamber pressure and the RF power was investigated in detail. The highest anisotropy and the lowest CD loss were achieved at the $SF_6$-rich compositions, i.e., $Cl_2:SF_6$=17:33 (SCCM), in the $POCl_3$-doped poly-Si. The etch rates increased for n-type dopant (phosphorus), while decreased for p-type (boron) with increasing the doping levels irrespective of plasma parameters. And from the results of the activation of doped poly-Si films the active carrier concentrations as well as the doping concentrations were found to be responsible for the increase of the etch rate of the phosphorus-doped poly-Si.

대소변불리(大小便不利)를 동반한 척추 압박골절 환자 치험 1례

박성호,박준식,송윤경,엄유식,Park, Sung-Ho,Park, Jun-Sik,Song, Yun-Kyung,Eom, Yu-Sik 척추신경추나의학회 2005 대한추나의학회지 Vol.6 No.1

In recent years, according to the increase of the osteoporosis and traffic accidents, the vertebral compression fracture patients are increased, This Study is clinical observation to the patients who be taken compression fracture of the $L1^{\sim}L2$ vertebra bodies with the symptoms of urinary disorder and ileus. She was treated by bed rest, acupuncture and moxibustion, herb medicine, physical therapy. In the observation of this case, I think that conservative treatment which involved acupuncture, moxibustion therapy and herb medicinal treatment is more effective than common nonoperative therapy.

산업부산물 재활용 건설자재와 우수재활용제품(GR) 인증제도

박성호,Park, Sung-Ho 한국건설순환자원학회 2016 한국건설순환자원학회지 Vol.11 No.3

감마과정 모델을 적용한 포구속도 저하량에 따른 저장수명 예측기법 연구

박성호,김재훈,Park, Sung-Ho,Kim, Jae-Hoon 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.5

The aim of the study is to investigate the method to estimate a storage life of propelling charge on the decrease of muzzle velocity by stochastic gamma process model. It is required to establish criterion for state failure to estimate the storage life and it is defined in this paper as a muzzle velocity difference between reference value and maximum allowable standard deviation multiplied by 6. The relationship between storage time and muzzle velocity is investigated by nonlinear regression analysis. The stochastic gamma process model is used to estimated the state distribution and the life distribution for storage time for 155mm propelling charge KM4A2 because the regression analysis is a deterministic method and it can't describe the distribution of life for storage time.

선별적 데이터 학습 기반의 베이지안 네트워크를 이용한 단기차량속도 예측

박성호,유영중,문상호,김영호,Park, Seong-ho,Yu, Young-jung,Moon, Sang-ho,Kim, Young-ho 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.12

정확한 교통정보의 예측은 출발지로부터 목적지까지의 최적경로를 제공할 수 있으며, 이로 인해 시간과 비용의 절감 효과를 얻을 수 있다. 본 논문에서는 다양한 교통정보 예측 방법 중 확률 모델을 기반으로 교통정보를 예측하는 베이지안 네트워크 방법을 이용한다. 기존 연구에서는 베이지안 네트워크 예측 방법이 모든 시간대에서의 데이터를 학습에 사용하는 것과는 달리, 본 논문에서는 예측하고자 하는 시간대와 동일한 요일과 시간에 해당하는 데이터만을 선별적으로 학습에 사용한다. 서로 다른 두 가지 학습방법에 따른 예측 결과의 정확도는 일반적으로 많이 사용되는 MAPE(Mean Absolute Percentage Error)로 검증하였으며, 서울 시내 14개의 링크 구간에 대해 실험을 진행하였다. 실험결과는 본 논문에서 제안한 방법이 모든 시간대의 데이터를 학습에 사용한 방법에 비해 MAPE의 관점에서 더 높은 정확도를 가진 교통 예측 값을 계산할 수 있음을 보여준다. The prediction of the accurate traffic information can provide an optimal route from the place of departure to a destination, therefore, this makes it possible to obtain a saving of time and money. To predict traffic information, we use a Bayesian network method based on probability model in this paper. Existing researches predicting the traffic information based on a Bayesian network generally used to study the data for all time. In this paper, however, only data corresponding to same time and day of the week to predict selectively will be used for learning. In fact, the experiment was carried out for 14 links zone in Seoul, also, the accuracy of the prediction results of the two different methods should be tested with MAPE (Mean Absolute Percentage Error) which is commonly used. In view of MAPE, experimental results show that the proposed method may calculate traffic prediction value with a higher accuracy than the method used to learn the data for all time zones.

재생아스콘과 우수재활용제품(GR) 인증제도

박성호,Park, Sung-Ho 한국건설순환자원학회 2015 한국건설순환자원학회지 Vol.10 No.4

고농도 포도당이 뼈모세포와 치주인대세포의 세포자멸사에 미치는 영향에 관한 연구

박성호,주성숙,홍정표,신제원,Park, Sung-Ho,Jue, Seong-Suk,Hong, Jung-Pyo,Shin, Je-Won 대한안면통증구강내과학회 2007 Journal of Oral Medicine and Pain Vol.32 No.4

This experiment was designed to clarify the effect of extracellular glucose on the osteoblasts and periodontal ligament cells. The cells were incubated for 24 and 48 hours with ${\alpha}$-MEM including 1,000 mg/L (control group) and 4,500 mg/L (experimental group) of glucose. Then, the expressions of caspase-3, p38 MAPK, JNK-1, and ERK-1 were examined using Elisa assay and Western blot. The results were as follows: 1. The expression of caspase-3 and p38 MAPK was increased by the high extracellular glucose in both cells. 2. The expression of caspase-3 and p38 MAPK was increased greatly in the periodontal ligament cells than the E1 cells by the high extracellular glucose. 3. The expression of JNK-1 was increased by the high extracellular glucose in both cells. 4. The expression of ERK-1 was not changed by the high extracellular glucose in both cells. These results suggest that extracellular glucose at high concentrations may inhibit the periodontal regeneration process increasing cellular apoptosis. And p38 MAPK and JNK-1 pathway may be the most responsible intracellular pathway rather than ERK-1.

Li$^+$ 이온성 고체전해질에 관한 연구

박성호,이두원,김규홍,최재시,Park Sung Ho,Lee Doo-Weon,Kim Keu Hong,Choi Jae Shi 대한화학회 1991 대한화학회지 Vol.35 No.4

$Li_2SO_4$를 기질로 한 Li$_2SO_4-CaSO_4$4 계를 합성하여 상온에서 700$^{\circ}C$까지의 온도구간에서 구조와 전도성을 연구하였다. CaSO$_4$의 몰비가 5${\%}$ 이상일 경우 Li$_2SO_4-CaSO_4$는 고용체를 형성하지 않음을 규명하였다. 치환되는 Ca$^{2+}$ 이온에 의해 단사정계에서 면심입방으로의 전이온도는 다소 낮아졌다. 단사정계의 전도도는 Ca$^{2+}$ 치환에 의해 생성되는 Li 공위에 의해 증가되나 면심입방구조의 전도도는 Ca$^{2+}$ 치환에 별 영향을 받지 않았다. The Li$_2SO_4$ system containing various mol${\%}$ of CaSO$_4$ were synthesized. The structure and the electrical conduction of these system were studied at the temperature from 20 to 700$^{\circ}C$. In the region of CaSO$_4$ mol ratio higher than 0.05, it could be confirmed that Li$_2SO_4-CaSO_4$ system does not form solid solution. Due to the substituted Ca$^{2+}$, the transition temperature (monoclinic to cubic) is shifted to the low temperature. The ionic conduction of monoclinic Li$_2SO_4-CaSO_4$ increased with increasing lithium vacancy which was produced by substituted Ca$^{2+}$, but that fcc Li$_2SO_4-CaSO_4$ was not influenced by the substituted Ca$^{2+}$ ion.

DCT-기반 영상/비디오 보안을 위한 암호화 기법 및 하드웨어 구현

박성호,최현준,서영호,김동욱,Park Sung-Ho,Choi Hyun-Jun,Seo Young-Ho,Kim Dong-Wook 대한전자공학회 2005 電子工學會論文誌-SP (Signal processing) Vol.42 No.2

년 논문에서는 MPEG과 JPEG, H.26X 계열 등의 DCT-기반 영상/비디오 컨텐츠에 효과적인 암호화 방법을 제안하였고, 이를 최적화된 하드웨어로 구현하여 고속동작이 가능하도록 하였다. 영상/비디오의 압축, 복원 및 암호화로 인한 많은 연산량을 고려하여 영상의 중요한 정보(DC 및 DPCM계수)만을 암호화 대상 데이터로 선정하여 부분 암호화를 수행하였다. 그 결과 암호화에 소요되는 비용은 원 영상 전체를 암호화하는 비용이 감소하였다. 여기서 Nf는 GOP내의 프레임수이고 PI는 B와 P 프레임에 존재하는 인트라 매크로블록의 수이다. 암호화 알고리즘으로는 다중모드 AES, DES, 그리고 SEED를 선택적으로 사용할 수 있도록 하였다. 제안한 암호화 방법은 C++로 구현한 소프트웨어와 TM-5를 사용하여 약 1,000개의 영상을 대상으로 실험하였다 그 결과 부분 암호화된 영상으로부터 원 영상을 추측할 수 없어 암호화 효과가 충분함을 확인하였으며, 이 때 암호화에 의한 압축률 감소율은 $1.6\%$에 불과하였다. Verilog-HDL로 구현한 하드웨어 암호화 시스템은 하이닉스 $0.25{\mu}m$ CMOS 팬텀-셀 라이브러리를 사용하여 SynopsysTM의 디자인 컴파일러로 합성함으로써 게이트-수준 회로를 구하였다. 타이밍 시뮬레이션은 CadenceTM의 Verilog-XL을 이용해서 수행한 결과 100MHz 이상의 동자 주파수에서 안정적으로 동작함을 확인하였다. 따라서 제안된 암호화 방법 및 구현된 하드웨어는 현재 중요한 문제로 대두되고 있는 종단간(end-to-end) 보안에 대한 좋은 해결책으로 유용하게 사용될 수 있으리라 기대된다. This thesis proposed an effective encryption method for the DCT-based image/video contents and made it possible to operate in a high speed by implementing it as an optimized hardware. By considering the increase in the amount of the calculation in the image/video compression, reconstruction and encryption, an partial encryption was performed, in which only the important information (DC and DPCM coefficients) were selected as the data to be encrypted. As the result, the encryption cost decreased when all the original image was encrypted. As the encryption algorithm one of the multi-mode AES, DES, or SEED can be used. The proposed encryption method was implemented in software to be experimented with TM-5 for about 1,000 test images. From the result, it was verified that to induce the original image from the encrypted one is not possible. At that situation, the decrease in compression ratio was only $1.6\%$. The hardware encryption system implemented in Verilog-HDL was synthesized to find the gate-level circuit in the SynopsysTM design compiler with the Hynix $0.25{\mu}m$ CMOS Phantom-cell library. Timing simulation was performed by Verilog-XL from CadenceTM, which resulted in the stable operation in the frequency above 100MHz. Accordingly, the proposed encryption method and the implemented hardware are expected to be effectively used as a good solution for the end-to-end security which is considered as one of the important problems.