샘플치 시스템의 루프정형 2자유도 H_{\infty}디지털 제어기 설계

이상철,박종우,조도현,이종용,이상효,Lee, Sang-Cheol,Park, Jong-U,Jo, Do-Hyeon,Lee, Jong-Yong,Lee, Sang-Hyo 대한전기학회 2000 전기학회논문지 D Vol.49 No.9

In this paper we propose a design procedure of loop-shaping two-degree-of-freedom H$\infty$ digital controller for sampled-data system. We extend the continuous time loop-shaping two-degree-of-freedom H$\infty$ control problem to sampled-data system. The configuration of generalized plant is modified for sampled-data system. And then using continuous lifting we obtain the digital controller. In the final stage of loop-shaping procedure the problem of absorbing weighting functions is discussed. We summarize this study to the design procedure and illustrate the application for an inverted pendulum on the cart.

광대싸리 줄기의 페놀성 화합물

이상철,안병태,박웅양,이승호,노재섭,이경순,Lee, Sang-Cheol,Ahn, Byung-Tae,Park, Woong-Yang,Lee, Seung-Ho,Ro, Jai-Seup,Lee, Kyong-Soon 한국생약학회 1996 생약학회지 Vol.27 No.1

Twelve compounds were isolated from stems of Securinega suffruticosa. On the basis of chemical and spectroscopic evidence, they were identified as gallic acid, corilagin, tercatain, geraniin, bergenin, norbergenin, 4-O-galloylnorberg-enin, 11-O-galloylnorbergenin, (+)-catechin, gallocatechin, isoquercitrin and rutin.

Euphorbia ebracteolata에 대한 생약학적 연구(I) -Euphorbia ebracteolata의 Flavonoid 성분-

이상철,안병태,박웅양,이승호,노재섭,이경순,유응걸,Lee, Sang-Cheol,Ahn, Beung-Tae,Park, Woong-Yang,Lee, Seung-Ho,Ro, Jai-Seup,Lee, Kyong-Soon,Ryu, Eung-Kul 한국생약학회 1992 생약학회지 Vol.23 No.3

Four flavonoids were isolated from the aerial parts of Euphorbia ebracteolata. On the basis of chemical and spectroscopic evidence, the structures of these compounds were established as $quercetin-3-O-{\beta}-D-glucoside$(isoquercitrin)(I), quercetin-3-O-rutinoside(rutin)(II), kaempferol-3-O-rutinoside(III) and $quercetin-3-O-(2'-O-galloyl)-{\beta}-D-glucoside$(IV) which was the main flavonoidal component in this plant. The isolation of flavonoids from E. ebracteolata is the first example.

백두산 화산활동 평가를 위한 화산가스 및 온천수에 대한 연구

이상철,윤성효,Lee, Sangchul,Yun, Sung-Hyo 대한자원환경지질학회 2017 자원환경지질 Vol.50 No.2

본 연구에서는 2015년 7월부터 2016년 8월까지 백두산 주롱 온천 지역에서 화산가스 및 온천수를 채취하여 분석을 실시하였다. 또한 이전 연구(Lee et al. 2014)에서 보고된 온천수의 측정값 중 $HCO_3{^-}$ 농도에 오류가 있음을 확인하고, 이를 개선하고자 했다. 온천수의 용존 $CO_2$는 이전 연구에서는 가스 크로마토그래프를 이용하여 분석하였지만, 이를 개선하여 2015년부터 TOC-IC를 이용하여 분석을 실시했다. 또한, 여러 농도의 $Na_2CO_3$ 표준 시료를 GC로 분석하여, 실제 농도와 표준시료 사이의 상관관계를 확인하였다. 그리고 이를 토대로 2014년 온천수의 용존 $CO_2$ 농도를 추정하고자 했지만, 실제 주롱(Julong) 온천 주변의 물을 채취하여 GC로 분석했을 때는 이 상관관계가 잘 적용되지 않아서 2014년 온천수의 용존 $CO_2$ 농도를 추정할 수가 없었다. 연구기간 동안 화산가스 내 $CO_2/CH_4$의 농도는 꾸준히 감소하였는데, 이에 대하여 두 가지 해석이 가능하다. 첫 번째는 화산체 내부의 환경이 조금 더 환원환경에 가까워져 상대적으로 화산가스 내 탄소가 $CO_2$ 보다는 $CH_4$ 또는 CO로 분배되기 유리해 진 것이다. 두 번째 가능성은 화산가스와 물의 상호작용이 강화되어 물에 대한 용해도가 훨씬 높은 $CO_2$의 농도가 상대적으로 감소한 것이다. 일반적으로 화산가스가 물에 희석되는 현상(scrubbing)의 영향은 화산활동이 활발한 시기보다는 잠잠한 시기에 강화된다. 한편, 온천수의 분석은 화산가스 연구에서 중요한 산성기체 성분의 음이온들과 주요 양이온, 그리고 Cd, Re, As에 대해 이루어졌다. This study performed the analysis on the volcanic gases and hot spring waters from the Julong hot spring at Mt. Baekdu during the period from July 2015 to August 2016. Also, we confirmed the errors that $HCO_3{^-}$ concentrations of hot spring waters in the previous study (Lee et al. 2014) and tried to improve the problem. Dissolved $CO_2$ in hot spring waters was analyzed using gas chromatograph in Lee et al. (2014). Improving this, from 2015, we used TOC-IC to analysis dissolved $CO_2$. Also, we analyzed the $Na_2CO_3$ standard solutions of different concentrations using GC, and confirmed the correlation between the analytical concentrations and the real concentrations. However, because the analytical results of Julong hot spring water were in discord with the estimated values based on this correlation, we can't estimate the $HCO_3{^-}$ concentrations of 2014 samples. During the period of study, $CO_2/CH_4$ in volcanic gases are gradually decreased, and this can be interpreted in two different ways. The first interpretation is that the conditions inside the volcanic edifice are changing into more reduction conditions, and carbon in volcanic gases become more favorable to distribute into $CH_4$ or CO than $CO_2$. The second interpretation is that the interaction between volcanic gases and water becomes greater than past, and the concentrations of $CO_2$ which have much higher solubility in water decreased, relatively. In general, the effect of scrubbing of volcanic gas is strengthened during the quiet periods of volcanic activity rather than active periods. Meanwhile, the analysis of hot spring waters was done on the anion of acidic gases species, the major cation, and some trace elements (As, Cd, Re).

광대싸리잎의 페놀성 화합물에 대한 화학적 연구

이상철,안병태,박웅양,이승호,노재섭,이경순,Lee, Sang-Chul,Ahn, Byung-Tae,Park, Woong-Yang,Lee, Seung-Ho,Ro, Jai-Seup,Lee, Kyong-Soon 한국생약학회 1994 생약학회지 Vol.25 No.2

A chemical examination of the aqueous acetone extract of the leaves of Securinega suffruticosa has led to the isolation of nine phenolic compounds. On the basis of chemical and spectroscopic evidences, the structures of these compounds were established to be gallic acid(1), corilagin(2), helioscopinin B(3), geraniin(4), bergenin (5), norbergenin(6), 11-O-galloyl norbergenin(7), gallocatechin(8) and rutin(9).

석회암 공동지역의 교량기초 보강에 관한 연구

이상철,류창열,조국환,Lee,Sang-Chul,Ryu,Chang-Yeol,Cho,Kook-Hwan 한국방재학회 2011 한국방재학회논문집 Vol.11 No.1

국내 강원도 지역에 광범위하게 분포하고 있는 불규칙한 석회암 공동(空洞)은 구조물의 사용성 저하 및 붕괴 등 예기치 못한 사고를 유발할 수 있다. 따라서 석회암 공동분포지역에서는 구조물의 기초지지력 증진을 위한 적절한 지반보강공사가 요구되며, 환경오염 문제를 최소화할 수 있어야 한다. 일반적으로 석회암 공동의 기초지지력 확보를 위해 시공하는 R.J.P(Rod Jet Pile) 공법은 주입재료를 시멘트모르타르를 사용하지만, 석회암 공동의 특성상 공동을 통한 시멘트성분의 유출로 인근지역의 식수오염과 양어장의 송어폐사가 발생하였다. 따라서 이러한 문제점을 해결하기 위해서 국내 외 적용가능한 보강공법들을 비교 검토하였으며, 실내시험을 통해 주입재료를 선정하였다. 또한, 1, 2단계로 구분하여 시공하고 선정된 보강재료 주입을 통해 저유동성 재료를 사용하는 비배출압밀공법을 한단계 향상시킨 몰탈압입공법을 제안하고 시험시공을 하였다. 시험시공 동안 인근지역 양어장의 수질변화가 거의 발생하지 않았으며, 시공위치에서 코어를 채취하여 압축강도를 측정한 결과 기준강도 5 MPa 이상으로 구조물의 기초지반 지지력을 확보하는 것으로 분석되었다. 따라서 몰탈압입공법은 주변 수질환경에 대한 친환경성을 확보함과 동시에 기초지반 지지력을 확보하는 것으로 검토 되었다. Irregular distributions of limestone cavity in Gang-Won province area may cause unexpected accidents from reduced serviceability or failure of structure. It is requested that an appropriate ground reinforcement method should be used to improve bearing capacity of structure, and the method should also be satisfied with environmental requirements. Among several methods used for foundation constructions in cavity area, Rod Jet Pile(RJP) method has been widely used. While the RJP method was used to improve bearing capacity for the railway bridge foundations, water pollutions of drinking water as well as fishery located adjacent to this project area were occurred. The main reason of the water pollution was cement runoff used in cement mortar during injecting material in RJP method. Laboratory tests were performed to prevent water pollution. The compaction mortar method using low movable material was selected for this project. The quality of water at a fishery adjacent to the site and the compressive strength of cores taken from the construction site were measured. Test results show that the water pollutions was minimized, and the average compressive strength of foundation material was over 5 MPa. As a result of this study, compaction mortar method can be used to ensure the bearing capacity of foundation and to prevent environment pollutions.

Kinetics of Isothermal Crystallization in Poly(ethylene oxide) and Poly(styrene-co-acrylic acid)Blends

이상철,이무성,조원호,Lee, Sang-Cheol,Lee, Mu-Seong,Jo, Won-Ho Materials Research Society of Korea 1991 한국재료학회지 Vol.1 No.3

시차주사 열분석기를 이용하여 poly(ethylene oxide)(PEO)/poty(styrene-co-acrylic acid) (SAA) blonds에 대한 등온 결정화 속도를 blend의 조성, 사용한 SAA의 공중합조성 및 결정화 온도에 따라 조사하였다. 실험결과는 Avrami 방정식을 이용하여 분석하였다. Avrami지수는 결정화 온도에 관계없이 거의 모든 blend 시료에서 2의 값을 나타내었다. 결정화 속도는 blend시료의 SAA 함량 및 사용한 SAA 공중합체의 아크릴산함량이 증가함에 따라 급격히 느려졌다. The kinetics of isothermal crystallization in blends of poly(ethylene oxide) (PEO) and poly(styrene-co-acrylic acid) (SAA) has been examined as a function of the blend ratio, the copolymer composition, and the crystallization temperature, based on the Avrami eauation. The Avrami exponents were mostly chose to 2, independent of the crystallization temperature. The crystallization rate of PEO in PEO/SAA blends decreased with the increase of SAA content. And also, the higher the acrylic acid content in the SAA copolymer, 7he slower the crystallization rate of PEO in the blends.

악하선(顎下線)과 협점막(頰粘膜)에 발생한 다형성(多形性) 선종(腺腫)의 치험례

이상철,김여갑,류동목,이백수,김병주,Lee, Sang-Chull,Kim, Yeo-Gab,Ryu, Dong-Mok,Lee, Baek-Soo,Kim, Byung-Ju 대한악안면성형재건외과학회 1993 Maxillofacial Plastic Reconstructive Surgery Vol.15 No.2

Pleomorphic adenoma is the most common of all salivary gland tumors, constituting over 50% of all cases of tumors of both major and minor salivary gland origin and approximately 90% of all benign salivary gland tumors. Of the major salivary glands, the parotid gland is the most common site of the pleomorphic adenoma. It may occur, however, in any of the major gland or in the widely distributed intraoral accessory salivary glands. The palatal glands are frequently the site of origin of tumors, and other parts of origins are as follows: upper and lower lip, buccal mucosa, tongue and occasionally other sites. The majority of the lesions are found in patients in the fourth to sixth decades, but they are also relatively common in young adults and have been known to occur in children. It is somewhat more frequent in women than men. The term "mixed tumor" has masquaeraded under a great variety of names throughout the years (e.g., enclavoma, branchioma, endothelioma, enchondroma), but the term "pleomorphic adenoma" suggested by Willis characterizes closely the unusual histologic pattern of the lesion. The accepted treatment for this tumor is surgical excision. The intraoral lesions can be treated somewhat more conservatively by extracapsular excision. In general, Lesions of the hard palate should be excised with the overlying mucosa, while those in lining mucosa, such as the lips, soft palate and buccal mucosa often can be treated successfully by enucleation or extracapsular excision. In our hospital, we experienced two patients who were identified pleomorphic adenoma which occurred at buccal mucosa, submandibular gland. The lesions were successfully treated by surgical excision.

암에 관한 소고

이상철,Lee, Sang-Cheol 대한한약협회 1997 大韓漢藥 Vol.1 No.-

자연순환형 친환경 축산정책 방향

이상철,Lee, Sang-Cheol 한국종축개량협회 2007 種畜改良 Vol.12 No.5