미세구조에 따른 La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ 분리막의 산소투과 및 기계적 특성

이시우,이승영,이기성,우상국,김도경,Lee, Shi-Woo,Lee, Seung-Young,Lee, Kee-Sung,Woo, Sang-Kuk,Kim, Do-Kyung 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.10

고상 반응법을 통해 $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ 페롭스카이트계 산소투과 분리막을 제조하였으며, 미세구조에 따른 산소투과 특성 및 기계적 특성을 고찰하였다. 분리막의 미세구조는 소결온도 및 소결 유지시간을 달리함으로써 조절하였으며, 미세구조에 따른 평균 입경 및 상대밀도의 변화를 평가하였다. 입계 분율의 감소에 따라 산소투과유속이 증가하는 경향을 나타내었으며, 본 연구에서 고찰한 소결조건 중에서는 1300${\circ}C$에서 10시간 유지하여 제조한, 상대밀도가 높고 비교적 입경이 조대한 분리막 시편의 경우, 최대 0.37 ml/$cm^2$${\cdot}$min의 산소투과유속이 특정되었다. 파괴강도는 소결체의 상대밀도에 의존적이었으며, 파괴인성은 결정립의 크기에 따라 증가하는 경향을 나타내었다. Oxygen permeability and the mechanical properties of mixed ionic-electronic conductive $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ perovskite-type membrane, fabricated by solid state reaction, were investigated with regard to microstructure. The microstructure of the membrane was controlled by changing the sintering temperature and holding time. The average grain size and relative density were evaluated as a function of sintering conditions. As the fraction of grain boundary decreased, oxygen permeability showed a tendency to increase. Especially the maximum oxygen flux of 0.37 ml/$cm^2$${\cdot}$min was measured for the specimen sintered at 1300${\circ}C$ for 10 h, which has high density and relatively large grain size. Fracture strength was dependent on the relative density of sintered body, while fracture toughness increased with average grain size.

환자용 사상체질진단 설문지의 체질별 응답차이에 관한 연구

이시우,주종천,이수경,이혜정,장은수,Lee, Si-Woo,Joo, Jong-Cheon,Lee, Su-Kyung,Lee, Hae-Jung,Jang, Eun-Su 사상체질의학회 2007 사상체질의학회지 Vol.19 No.3

1. Objectives This study aims to evaluate newly developing Sasang Constitution Diagnosis Questionnaire for accuracy and efficiency. 2. Methods Three hundred and twenty eight patients from 4 multi centers are involved in this study. Excluding 16 constitution-unidentified patients and 2 Taeyang-in patients, 310 patients' questionnaires are analyzed statistically by their constitutions. 3. Results Sixty one questions are statistically significant in whole 229 questions of Sasang Constitution Diagnosis Questionnaire. We have selected 30 questions from 61 questions by comparing total data from 4 multi centers with those of each center. Thirty questions are made up of 10 body shape questions, 10 appearance questions, 5 character questions and 5 symptom questions. 3. Conclusions There might be needs for revision of character and symptom questions. From results, we suggest to diagnose Sasang Constitution for screening by short-form questionnaire consisted of questions on body shapes and appearances.

대학에 바란다 - 대학과 고등학교의 연계를 통한 미래인재 육성

이시우,Lee, Si-U 한국대학교육협의회 2012 大學敎育 Vol.175 No.-

연속음성에서 천이구간의 탐색, 추출, 근사합성에 관한 연구

이시우,Lee, Si-U 한국정보처리학회 2000 정보처리논문지 Vol.7 No.4

In a speed coding system using excitation source of voiced and unvoiced, it would be involved a distortion of speech quality in case coexist with a voiced and an unvoiced consonants in a frame. So, I propose TSIUVC(Transition Segment Including UnVoiced Consonant) searching, extraction ad approximation-synthesis method in order to uncoexistent with a voiced and unvoiced consonants in a frame. This method based on a zerocrossing rate and pitch detector using FIR-STREAK Digital Filter. As a result, the extraction rates of TSIUVC are 84.8% (plosive), 94.9%(fricative), 92.3%(affricative) in female voice, and 88%(plosive), 94.9%(fricative), 92.3%(affricative) in male voice respectively, Also, I obain a high quality approximation-synthesis waveforms within TSIUVC by using frequency information of 0.547kHz below and 2.813kHz above. This method has the capability of being applied to speech coding of low bit rate, speech analysis and speech synthesis.

제지애쉬를 혼입한 모르터의 특성에 관한 실험적 연구

이시우,Lee, Si-Woo 한국건축시공학회 2002 한국건축시공학회지 Vol.2 No.3

The purpose of this study is investigating characteristics of paper-ash mortar according to partial replacement of fine aggregate by Paper-ash. For this purpose, selected test variables were mixing ratio with two levels of mortar(1:2, 1:3), and 3 types of paper-ash(A, B, C), and paper-ash content with four levels(5%,, 10%, 15%, 20%). As a result of this study, in all mixes with partial replacement of fine aggregate by Paper-ash generally Produced Paper-ash mortar with decreased compressive strength at ail age as compared to ordinary mixes. The mixing rate 1:2 was the higher increasing rate of strength than the mixing rate 1:3. The flow value and unit weight of paper-ash mortar were decreased with increasing of the paper-ash content. And the thermal conductivity of the thermal conductivity of the paper-ash mortar was lower than normal mixing without paper-ash.

외측연수증후군(外側延髓症候群)(wallenberg syndrome)으로 진단받은 태음인환자를 치료한 1예(例)에 대한 증예보고(症例報告)

이시우,박혜선,김경요,김형순,Lee, Si-Woo,Park, Hye-Sun,Kim, Kyung-Yo,Kim, Hyoung-Soon 사상체질의학회 2001 사상체질의학회지 Vol.13 No.2

If the proximal portion of the fourth segment of the vertebral onery is occluded before the posterior inferior cerebellar artery branch, ischemia usually affects the lateral medulla oblongata or the ipsilateral side of the cerebellum. The lateral medullary syndrome(wallenberg syndrome) resulting from occlusion in this area is common. 62 years old male who has swallowing difficulty, dizziness and diagnosed as the lateral medullary syndrome(wallenberg syndrome) is admitted in Wonkwang university oriental medical hospital Kwangju. We have diagnosed him as Taeumin and treated by east integrated therapy. We classified this as Taenmin-liyoiljung(太陰人 裏熱症) and prescribed chungsimyoinjatang(淸心蓮子湯) to the principle of cheongganjoyoil(淸肝燥熱). In the result, we had the improvement of the symptoms. This report described the process and contents about the way the patient was cured.

슈메이커-레비 9 혜성의 목성 충돌관측

이시우,김승리,성환경,표태수,Lee, Si-Woo,Kim, Seung-Ri,Seong, Hwan-Gyeong,Pyo, Tae-Su 한국천문학회 1995 天文學論叢 Vol.10 No.1

We observed impact spots on Jupiter which were formed by the collision with fragments of Shoemaker-Levy 9 comet during the period from 17 July to 13 August, by using the SNU 61cm reflector combined with CCD camera and DBVRI filters. In order to get more clear image of impact spots, the observed data were processed by the unsharp masking method, high-pass filtering method and Richardson-Lucy algorithm after the basic processing through IRAF package. The sizes of impact spots range from 2000km to 1000km, and from this size, the original size of comet fragments before collision with Jupiter is estimated to be less than ${\sim}3km$. From the observed rotating rate of impact spots, the rotational period of Jupiter is determined as $9^h$ $56^m$ $32^s$ at the southern latitude of $47^{\circ}{\sim}49^{\circ}$.

$V_{1-x}M_xO_2$박막의 thermochromism에 대한 연구

이시우,이문희,Lee, Si-U,Lee, Mun-Hui 한국재료학회 1994 한국재료학회지 Vol.4 No.6

"Smart window"에 코팅재료로 쓰이는 thermochromic $Vo_{2}$박막을 전자빔 증착 방법으로 유리 기판위에 증착시켜 $0^{\circ}C$-$90^{\circ}C$ 온도범위에서 가시광 및 근적외선의 투과율을 spectrophotometer로 측정하였다. $300^{\circ}C$의 기판온도와 $400^{\circ}C$ 어닐링 온도가 $VO_{2}$ 박막이 결정화되기 때문인 것으로 확인되었다. 또한, $VO_{2}$박막을 알곤중에서 어닐링하면 500nm이하의 파장에서는 그 투과율이 상당히 낮아지는 것으로 나타났다. W가 5a/0첨가된 $V_{0.95}W_{0.05}O_{2}$박막은 약 $0^{\circ}C$의 천이돈도를 나타내었고 Sn이 0.5a/o $V_{0.995}W_{0.005}O_{2}$박막의 경우에는 $300^{\circ}C$의 기판온도에서 증착한 후 $450^{\circ}C$/5시간 동안 알곤가스 중에서 어닐링하였을때 뚜렷한 thermochromism을 나타내었으며 이 박막의 천이온도는 실용가능한 온도인 약 $25^{\circ}C$로 발견되었으며 약간의 이력곡선이 나타났다.력곡선이 나타났다. Thermochromic $Vo_{2}$ thin films for "smart windows" were prepared by electron beam evaporationmethod on a glass substrate and spectral transmittances were examined by spectrophotometer. Substratetemperature of $300^{\circ}C$ and annealing temperature of $400^{\circ}C$ were found to be effective to give athermochromism on $Vo_{2}$ thin film due to the crystallization of the thin film. Furthermore, annealing of$Vo_{2}$ thin film affected the spectral transmittance and reduced the transmittance significantly at wavelengthbelow 500nm.$V_{0.95}W_{0.05}O_{2}$ thin film doped by 5 atomic percent of W showed semiconductor-metal transition around 0$0^{\circ}V_{0.995}W_{0.005}O_{2}$thin film which contains 0.5 atomic percent Sn showed therrnochrornisrn when it was depositedat substrate temperature of $300^{\circ}C$ and annealed at $450^{\circ}C$ for 5 hours in argon gas. The transitiontemperature of the $V_{0.995}W_{0.005}O_{2}$ thin film was found to be about $25^{\circ}C$ and showed some hysterisis. and showed some hysterisis.

어레이 압저항 센서를 활용한 체질맥 임상연구

이시우,주종천,김경요,김종열,Lee, Si-Woo,Joo, Jong-Cheon,Kim, Kyung-Yo,Kim, Jong-Yeol 사상체질의학회 2006 사상체질의학회지 Vol.18 No.1

1. Objective Pulse diagnosis is generally applied to Traditional Oriental Medicine but not to Sasang Constitution diagnosis. Recently new pulse analyzer using array piezoresistive sensor and multi-channel robot arm developed. It reflects Oriental Medical Doctors' diagnostic processes, and its reproducibility test was done at Korea Institute of Oriental Medicine. We performed this study to set parameters diagnosing Sasang Constitution. 2. Methods One hundred thirty three subjects participated in this study. They are healty and approved this study. Before being tested with pulse analyzer, they had interview with Sasang Constitution Specialist to diagnose their Sasang Constitution. We established some useful parameters from parameters of pulse analyzer according to the Original Texts of Oriental Medicine and clinical experiences to analyze with clinical data of this study. 3. Results (I) There is a significant difference in pre-dicrotic notch time among all parameters of pulse analyzer in Sasang Constitution groups(P=0.047). (2) There is a significant difference in maximum pulse pressure in 33 to 48 year Sasang Constitution groups(P=0.010). (3) There is a significant difference in frequency width in 17 to 32 year Sasang Constitution groups(P=0.002). (4) There is a significant difference in CFS value in groups which OMD diagnoses; Floating & Sinking pulse(P=0.020). (5) There is a significant difference in pulse rate in groups which OMD diagnoses; Rapid & Slow pulse(P=0.000). (6) There is a significant difference in maximum pulse pressure in groups which OMD diagnoses; Deficient & Solid pulse(P=0.000). 4. Conclusions Analyzing parameters in each Sasang Constitution group, we found it shows significant difference in maximum pulse pressure and corresponding tendency in coefficient of floating & sinking pulse with theories of Sasang Consti-tutional Medicine. As we accumulate more clinical data, we will establish algorithm to diagnose Sasang Constitution using a pulse analyzer.

액상 구리 전구체 hfac (hexafluoroacetylacetonate) Cu(I) DMB (3,3-dimethyl-1-butene)의 특성 평가

이시우,강상우,한상호,Lee, Si-U,Gang, Sang-U,Han, Sang-Ho 한국재료학회 1999 한국재료학회지 Vol.9 No.11

본 연구에서는 기존에 알려진 구리 전구체와 새롭게 개발된 전구체인 hfac (hexafluoroacetylacetonate) Cu(I) DMB (3,3-dimethyl-1-butene)를 비교 평가해보았다. (Hfac)Cu(I) (DMB)의 증가압은 $40^{\circ}C$에서 3 torr 정도로 기존에 잘 알려진 (hfac)Cu(I) vinyltrimethylsilane (VTMS) 보다 10배 정도 높은 것으로 나타났으며 그럼에도 불구하고 상당히 안정하여 $65^{\circ}C$에서 일주일 이상 가열하여도 변하지 않았다. 이 전구체로 100-$280^{\circ}C$에서 구리 박막을 증착할 수 있었으며 150-$250^{\circ}C$온도 범위에서 2.0$\mu\Omega$-cm의 순수한 구리 박막을 얻었다. 구리 박막의 증착 속도는 기존의 전구체보다 7~8배 정도 높은 것으로 나타났다. An organometallic precursor, hfac(hexafluoroacetylacetonate) Cu(I) DMB (3,3-dimethyl- 1-butene) was synthesized, evaluated and compared with other precursors for metal organic chemical vapor deposition of copper thin films. It was found that at $40^{\circ}C$, the vapor pressure was an order of magnitude higher (about 3 torr) than (hfac) Cu vinyltrimethylsilane (VTMS) and films could be deposited at the substrate temperature of 100-$280^{\circ}C$ with deposition rate substantially higher. The copper films contained no detectable impurities as measured by Auger electron spectroscopy and had a resistivity of about 2.0$\mu\Omega$-cm in the deposition temperature range of 150 to $250^{\circ}C$. From the thermal analysis, (hfac)Cu(I)(DMB) is believed to be quite stable and no appreciable amount of precipitation was observed at $65^{\circ}C$ heating for more than a month.