압전 액튜에이터의 특성 및 기술동향

엄우식,송준광,이해욱 ( Woo Sik Um,Jun Kwang Song,Hae Wook Lee ) 한국전기전자재료학회 1997 전기전자재료학회논문지 Vol.10 No.7

전자 세라믹 분체의 특성 평가 방법

엄우식,이인식 한국전기전자재료학회 1995 電氣電子材料學會誌 Vol.8 No.3

본 논문에서는 분체 특성 평가 연구의 국제 동향과 입자형태, 입도분포, 비표면적, 분체밀도, 기공도, 화학분석 평가분야의 기본원리, 특히 측정시 변수들의 영향과 이러한 특성변화에 따른 전기적성질 변화에 대하여 간단히 언급을 하였다. 분체 특성평가분야의 연구는 선진국에 비해 낙후되어 있고 관심도 또한 낮은 형편이다. 이 분야의 학문적, 산업적인 중요점을 고려할 때, 분체 특성 평가에 대한 기초 및 응용연구가 활성화되었으면 한다.

압전 액튜에이터의 특성 및 기술동향

엄우식,송준광,이해욱 한국전기전자재료학회 1997 電氣電子材料學會誌 Vol.10 No.7

분무 건조된 세라믹 과립의 강도 측정방법에 대한연구

엄우식,이희수,이세훈,김덕희,이인식 한국세라믹학회 1996 한국세라믹학회지 Vol.33 No.6

We have studied the test method for strength of spray dried ceramic powder using manual press and UTM. which is one of the important to influence forming process. We could observe the compaction behavior using manual press. However the measurement of granule strength was only possible with UTM capable of providing the condition of a constant pressing rate. The strength of granule can be measured from the slope change of compaction curve and agrees with the value which is obtained from the combination of saturated tap density and compaction curve. So we proposed the accurate method to measure the strength of granule from the results of this study.

통원 수술 환자의 퇴원 기준으로서 PAR Score와 Modified PADSS의 유용성

엄우식,이가영,김광우,최익현,전윤석,권윤상,김유홍 대한마취과학회 1998 Korean Journal of Anesthesiology Vol.35 No.5

Background : Although an ambulatory surgical practice continues to increase, there is a few data exist about patient discharge criteria. This study was undertaken to evaluate the usefulness and safety of Aldrete PAR (postanesthetic recovery) score and modified PADSS (modified postaneathesia discharge scoring system) on ambulatory surgery patients for recovery in Korea. Methods : Demographic, anesthetic data, Aldrete PAR score and modified PADSS on 279 patients were recorded. The time to dicharge, from recovery room and postoperative complications were evaluated, also. Results : PAR score and modified PADSS are correlated to length of stay in ambulatory surgery center. 24hr after discharge, 16% patients complained postoperative complications. Pain was most frequent postoperative complication. The PAR score was correlated with the occurrence of the complication. Conclusion : PAR score and modified PADSS are useful scoring systems to evaluate patients and make a decision to discharge the patients from ambulatory surgery center in safe. (Korean J Anesthesiol 1998; 35: 983∼987)

침입차단시스템의 보안성 품질평가 방법론 개발

엄우식,전인오,양해술 보안공학연구지원센터(JSE) 2010 보안공학연구논문지 Vol.7 No.5

본 연구에서는 침입방지시스템의 기반기술을 조 사하고 침입방지시스템의 품질시험․평가를 위한 품질특성을 분석하였다. 본 연구에서는 기존의 소프트웨어 품질 평가 기술 및 표준화에 관한 관련 연구를 추진하고, 침입방지시스템 보안성 및 그 외 주특성에 대한 품질 평가 모델을 개발하였다. 또한, 현재 품질 평가 국제 표준화 동향에 있어서도 기존에 소프트웨어 품질 평가를 위해서 지침서로 사용하였던 소프트웨어의 품질 평가 국제 표준화 문서 ISO/IEC9126과 ISO/IEC 14598을 통해서 품질 평가 모델을 개발하였다. In this Study, base technology of intrusion prevention system was investigated and quality characteristics for quality test and evaluation of intrusion prevention system were analyzed. Moreover, research related to existing software evaluation technology and standardization was pursued, and quality evaluation model for the security nature as well as other main features of intrusion prevention system was developed in this Study. In addition, with regards to the current trend in the international standardization of quality evaluation, quality evaluation model was developed through the ISO/IEC9126 and ISO/IEC 14598, which are the existing international standardization documents on the quality evaluation of software that have been used as guideline for quality evaluation of software.

Preparation of High Tc Superconductor Powders by Emulsion Drying Method

엄우식,김호기,Eom, Woo-Sik,Kim, Ho-Gi Materials Research Society of Korea 1991 한국재료학회지 Vol.1 No.2

The superconducting powders in $YBa_2Cu_3O_{7-x}$ and Bi-Pb-Sr-Ca-Cu-O system were easily prepared from water in oil type emulsion by loading each cation into the aqueous phase. In $YBa_2Cu_3O_{7-x}$ system, the superconducting orthorhombic phase was formed by calcining at $750^{\circ}C$ for 10h in $O_2$. The size of the superconducting phase powders was submicron. The density of the sintered specimen using this powders was about 95% of the theoretical density and the resistance sharply decreases at about 90K, In Bi-Pb-Sr-Ca-Cu-O system the low Tc phase($(Bi, Pb)_2Sr_2Ca_1Cu_2O_y$) was formed by calcining at $800^{\circ}C$ for 10h in a low oxygen partial pressure of 1/20 atm The shape of clacined powder is thin plate of which size is about $2\mu\textrm{m}$ and thickness is smaller than $\mu\textrm{m}$. It was observed that the high Tc phase ($(Bi, Pb)_2Sr_2Ca_2Cu_3O_y$) was formed by sintering at $850^{\circ}C$ for 30h in oxygen pressure of 1/20 atm without intermediary grinding. The above sintered sample exhibited superconductivity with a Tc(zero)=105K.

지문인식시스템의 신뢰성 품질 성능 평가모델 개발

엄우식(Woo-Sik Eom),전인오(In-Oh Jeon) 한국콘텐츠학회 2011 한국콘텐츠학회논문지 Vol.11 No.2

현재 지문인식시스템 제품은 양적으로 빠른 성장세를 보이고 있으나 그 동안 질적인 품질을 고려하는 노력이 미흡한 것이 사실이었다. 따라서, 본 논문에서는 지식정보보안 제품의 질적인 면을 평가하여 품질수준을 파악하여 개선방향을 도출함으로써 품질향상을 지원할 수 있는 평가모델을 개발하기 위해 지문인 식시스템 제품의 국내외 시장현황과 기술적인 요소들을 분석하였다. 제품의 특성을 고려하여 보안성, 성능, 신뢰성 요구사항을 분석하여 기존 보안기능 중심의 평가에서는 다루지 못했던 비 기능 요소를 포괄적으로 적용할 수 있는 신뢰성 품질평가 모델을 구축하였다. 본 논문을 통해 지문인식 제품 특성과 동향을 반영하고 제품별 평가를 수행할 수 있는 신뢰성 평가모델을 구축함으로써 지식정보보안 제품의 전반적인 품질향상에 기여할 수 있을 것이다. Although products with the fingerprint recognition system currently show a rapid growth in quantity, it is also true that efforts to consider the product quality have been lacking until now. Accordingly, this paper analyzed technological elements with domestic and foreign market situations for products with the fingerprint recognition system to develop an evaluation model to support the quality increase by evaluating aspects of product quality for the knowledge information security, identifying the level of quality and deriving directions for improvements. A model for the reliability quality evaluation was constructed that can be applied comprehensively to non-functional elements that have not been done in the existing evaluations central to the security functions by analyzing requirements for the security, performance and reliability in consideration of features on products. It is considered that this paper can make contributions to the overall quality increase for products with the knowledge information security by reflecting features and trends for the fingerprint recognition products and building a model for the reliability and evaluation to perform evaluations by product.

소성 조건에 따른 WO$_3$계 후막센서소자의 제조 및 응답특성

정용근,엄우식,이희수,최성철 한국마이크로전자및패키징학회 1999 마이크로전자 및 패키징학회지 Vol.6 No.2

가스 감지막의 미세구조와 비화학량론 구조의 변화에 따른 응답특성의 거동을 고찰하기 위하여 소성 조건을 변화시키면서 $WO_3$후막형 가스센서를 제조하였다. 소자는 감지물질인 $WO_3$분말과 유기 용제를 균일하게 혼합한 페이스트를 Au전극과 $RuO_2$발열체가 입혀진 알루미나 기판 위에 스크린 프린팅 방법으로 제조하였다. 소성 조건을 변화시키기 위하여 600-$800^{\circ}C$ 온도범위하에서 1시간 동안 열처리 하였고, Ar과 $O_2$가스의 비율을 변화시키면서 $700^{\circ}C$에서 1시간 재열처리하였다. 열처리 결과, 소성 온도 $700^{\circ}C$에서 제조된 $WO_3$가스센서 소자가 가스감도 210, 응답속도 2초로 가장 좋은 특성을 보였으며 Ar과 $O_2$가스의 비율이 40-50%의 소성 분위기에서 가스 감도가 가장 높게 나타났다. We have fabricated $WO_3$ thick film gas sensor under various firing conditions in order to study gas sensing properties in terms of the variation of microstructure and non-stoichiometric structure of gas sensing layer. $WO_3$ paste mixed homogeneously with organic vehicle was coated by screen printing method on alumina substrate composed of Au electrode and $RuO_2$heater on each side. To change filing condition, sensing materials were fared at 600-$800^{\circ}C$ for 1 hour and refired at $700^{\circ}C$ for 1 hour in the mixtures of $_Ar/O2$gas. In the result of heat-treatment, $WO_3$ gas sensor fared at $700^{\circ}C$ showed best gas sensing properties of 210 gas sensitivity and 2 second response time and the best firing environment was 40-50% of $Ar/O_2$gas.

먼지/유해가스 동시 처리용 세라믹 필터 개발에 관한 연구 (2)

김영배,엄우식,이희수,박신서,정경원,장성기 대한환경공학회 1999 대한환경공학회 학술발표논문집 Vol.1999 No.8