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.

사상체질 임상 연구 현황에 대한 조사연구;사상체질의학회지를 중심으로

이시우,황지호,유종향,오승윤,주종천,장은수,Lee, Si-Woo,Hwang, Ji-Ho,Yu, Jong-Hyang,Oh, Seung-Yun,Joo, Jong-Cheon,Jang, Eun-Su 사상체질의학회 2008 사상체질의학회지 Vol.20 No.2

1. Objectives and Methods It has been examined 703 papers of Sasang Constitution Society published from 1989 to 2007. Among them, the study methods have been classified focused on 332 papers related to clinical research and the method of constitution diagnosis and subjects have been researched to research the reality of the clinical research of Sasang Constitutional Medicine. 2. Results 1. The rest studies are the most which can not be classified by existing study method among 332 clinical studies. 2. The study of patient control group is 17 cases and the clinical experiment is one case, so highly well-grounded studies have not been performed. 3. The most method of constitution diagnosis is the constitution diagnosis by experts and by QSCC. 4. The number of constitution diagnosis method performed in the research institution is within 2. They are 254 cases(89.5%). 5. The studies which utilize more than 3 constitution methods are 22 cases and the studies that use medical rash are 7cases(31.8) 6. The 215 cases that subjects are less than 100 are the most and 100${\sim}$500 subjects are 71 cases. 500${\sim}$10000 subjects are 33 cases and more than 1000 subjects are 15 cases. 3. Conclusions Therefore, it is needed to increase the rate of highly well-grounded studies and set the standard criteria by providing constitution diagnosis guideline.

초기질량함수(初期質量函數)

이시우,Lee, Si-U 한국천문학회 1990 天文學論叢 Vol.5 No.1

Some important problems for the bimodal initial mass function(IMF) of field stars in the solar neighborhood, the relation of the IMF of field stars with the combined IMF of open star clusters and the time-dependent IMF of young star clusters are discussed particularly by comparing their observed and computed present day mass functions.

최소 자승법을 이용한 TSIUVC 근사합성법에 관한 연구

이시우,Lee, See-Woo 한국정보처리학회 2002 정보처리학회논문지B Vol.9 No.2

유성음원과 무성음원을 사용하는 음성부호화 방식에 있어서, 같은 프레임 안에 모음과 무성자음이 있는 경우에 음성 파형에 일그러짐이 나타난다. 본 논문에서는 최소 자승법을 적용한 새로운 TSIVUC 근사합성법을 제시하였다. 이 방법에서 TSlUVC의 추출에는 zero crossing rate과 FIR-STREAK 필터의 잔차신호를 이용한 개별피치 추출 알고리즘을 사용하였다. 실험결과, 최소 자승법을 적용하여 양호한 TSIUVC 근사합성 파형을 얻을 수 있었다. 또한 최대 오타신호에 있어서의 주파수 신호가 일그러짐이 적은 근사합성 파형에 중요한 역할을 한다는 것이다. 이 방법은 음성합성, 음성분석, 새로운 Voiced/Silence/TSIUVC의 음성부호화 방식에 활용할 수 있을 것으로 기대된다. In a speech coding system using excitation source of voiced and unvoiced, it would be involves a distortion of speech waveform in case coexist with a voiced and an unvoiced consonants in a frame. This paper present a new method of TSIUVC (Transition Segment Including Unvoiced Consonant) approximate-synthesis by using Least Mean Square. The TSIUVC extraction is based on a zero crossing rate and IPP (Individual Pitch Pulses) extraction algorithm using residual signal of FIR-STREAK Digital Filter. As a result, This method obtain a high Quality approximation-synthesis waveform by using Least Mean Square. The important thing is that the frequency signals in a maximum error signal can be made with low distortion approximation-synthesis waveform. This method has the capability of being applied to a new speech coding of Voiced/Silence/TSIUVC, speech analysis and speech synthesis.

경쟁력 강화와 효율성 제고를 위한 공개

이시우,Lee, Si-U 한국대학교육협의회 1997 大學敎育 Vol.87 No.-

대학에 바란다 - 대학과 고등학교의 연계를 통한 미래인재 육성

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

한약과 전기침치료가 비만환자의 체성분변화에 미치는 영향

이시우,이수경,Lee, Si-Woo,Lee, Su-Kyung 대한동의생리학회 2006 동의생리병리학회지 Vol.20 No.6

This study was aimed at finding out changes in body composition of obese patients, such as body weight, body fat mass and lean body mass. The subjects of this study are 33 females and 6 males who are from obesity clinic at Gunsan medical center. We measured body composition using BIA(Bioelectrical Impedence Analysis) to compare pre-treatment with post-treatment. The measured data were analyzed by paired t-test using SPSS. Differences were considered significant at P<0.05. Body weigh, body fat mass and lean body mass were reduced each by $3.76{\pm}23.41{\;}kg,{\;}2.29{\pm}1.96kg{\;}and{\;}1.59{\pm}1.38kg$ at a significant level after 4 week-treatment.

8kbps에 있어서 PCFBD-MPC에 관한 연구

이시우,Lee, See-woo 한국인터넷정보학회 2017 인터넷정보학회논문지 Vol.18 No.5

유성음원과 무성음원을 사용하는 멀티펄스 음성부호화 방식에 있어서, 대표구간의 멀티펄스 음원을 사용하는 경우에 유성음의 합성음성파형에서 일그러짐이 나타난다. 이러한 원인은 대표구간의 멀티펄스를 피치구간마다 복원하는 과정에서 재생 음성파형이 정규화 되는 것이 원인으로 작용한다. 본 논문에서는 합성 음성파형의 일그러짐을 제어하기 위하여 V/UV/S(Voiced / Unvoiced / Silence)의 스위칭을 사용하고, 피치구간 마다 멀티펄스의 위치를 보정하며, 무성자음(Unvoiced)의 근사합성에 특정주파수를 이용하는 PCFBD-MPC(Position Compensation Frequency Band Division-Multi Pulse Coding)를 제안하였다. 또한 8kbps의 부호화 조건에서 PCFBD-MPC 시스템을 구현하고, PCFBD-MPC의 SNRseg를 평가하였다. 그 결과 PCFBD-MPC의 남자음성에서 13.8dB, 여자음성에서 13.4dB 임을 확인할 수 있었다. 향후 멀티펄스 음원의 진폭과 위치를 동시에 보정하는 8kbps 음성부호화 방식의 음질을 평가하는 연구를 수행하고자 한다. 향후, 멀티펄스 음원의 진폭과 위치를 동시에 보정하는 8kbps 음성부호화 방식의 음질을 평가하는 연구를 하고자 한다. 이러한 방법들은 셀룰러폰이나 스마트폰과 같이 낮은 비트율의 음원을 사용하여 음성신호를 부호화하는 방식에 활용할 수 있을 것으로 기대된다. In a MPC coding using excitation source of voiced and unvoiced, it would be a distortion of speech waveform. This is caused by normalization of synthesis speech waveform of voiced in the process of restoration the multi-pulses of representation section. This paper present PCFBD-MPC( Position Compensation Frequency Band Division-Multi Pulse Coding ) used V/UV/S( Voiced / Unvoiced / Silence ) switching, position compensation in a multi-pulses each pitch interval and Unvoiced approximate-synthesis by using specific frequency in order to reduce distortion of synthesis waveform. Also, I was implemented that the PCFBD-MPC( Position Compensation Frequency Band Division-Multi Pulse Coding ) system and evaluate the SNRseg of PCFBD-MPC in coding condition of 8kbps. As a result, SNRseg of PCFBD-MPC was 13.4dB for female voice and 13.8dB for male voice respectively. In the future, I will study the evaluation of the sound quality of 8kbps speech coding method that simultaneously compensation the amplitude and position of multi-pulse source. These methods are expected to be applied to a method of speech coding using sound source in a low bit rate such as a cellular phone or a smart phone.

[상한론(傷寒論)]의 세 가지 승기탕증(承氣湯證)에 대한 사상의학적(四象醫學的) 고찰(考察)

이시우,Lee, Si-U 사상체질의학회 1997 사상체질의학회지 Vol.9 No.1