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).

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.

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.

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.

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).

경찰 ${\cdot}$ 경호직 종사자 무도교육 발전방안

이상철,Lee, Sang-Cheol 한국경호경비학회 2004 시큐리티연구 Vol.- No.7

측두근-오훼돌기 피판을 이용한 안와저의 재건 예

이상철,김여갑,류동목,최재용,Lee, Sang-Chull,Kim, Yeo-Gab,Ryu, Dong-Mok,Choi, Jae-Yong 대한악안면성형재건외과학회 1993 Maxillofacial Plastic Reconstructive Surgery Vol.15 No.1

The maxillary squamous cell carcinoma is major part of maxillary malignant tumor. The treatment of maxillary malignancy tumor is the maxillectomy in combination with radiation therapy and chemorherapy. When tumor invasion is occured to the orbit, orbital exenteration is required. But if the periosteum of the orbital floor is intact, the orbit can be preserved. There are many orbital floor reconstruction materials for the prevention of ptosis of the orbital content. The patients on this paper were diagnosised as squamous cell carcinoma on maxilla, we performed the partial maxillectomy including the orbital floor, and we used temporalis muscle-coronoid process flap for the reconstruction of the orbital floor after partial maxillectomy and obtained good esthetic and functional results, as followed. 1. We obtained sufficient flap width for defect of orbital floor. 2. It permits good blood supply and no necessary other donor site. 3. It gives a solid base for the support the globe and the orbital floor. 4. It gives minimal postoperative morphorogical defect and functional disturbance.

Determinants of Effecting Customer Loyalty : Comparison among Korean, Japanese and Chinese Online Game Market

이상철,상균영,구자철,서영호,Lee, Sang-Chul,Xiang, Jun-Yong,Gu, Ja-Chul,Suh, Yung-Ho The Korean Operations Research and Management Scie 2006 經營 科學 Vol.23 No.2

The purposes of this research are to identify causalities among flow and customer loyalty In Chinese online games, and to identify the factors by which flow are influenced. This research tests the model with Chinese on-line game users and compare this result with Korea and Japanese results which were conducted by Lee's research. These implications are thought to be helpful for Korean online game companies to understand the Chinese online game user and to develop the penetration strategies. The results indicated that significant Path coefficients to flow were the convenience of operator, the provision of information, the reality of design. The results indicated that significant path coefficients to customer loyalty were the involvement of virtual community and flow. The involvement of virtual community to flow was not significant but to customer loyalty was significant. The provision of information was negatively influenced on flow. The result of comparison indicated that the path coefficients were different among nations. Korea online game companies need to develop the indigenized online game and to Provide the information to their Chinese partner correctly and quickly.

Open Partial Nephrectomy vs. Robot-Assisted Partial Nephrectomy for a Renal Tumor Larger than 4 cm: a Propensity Score Matching Analysis

이상철,Ryu Hoyoung,Lee Jeong Woo 대한의학회 2021 Journal of Korean medical science Vol.36 No.20

Background: To compare open partial nephrectomy (OPN) and robot-assisted partial nephrectomy (RAPN) in the management of renal tumors larger than 4 cm. Methods: Clinical records of 220 patients who underwent OPN or RAPN for a single renal tumor ≥ 4.0 cm with a normal contralateral kidney were reviewed. After determining the propensity score, surgical parameters, functional outcomes, and oncological outcomes were compared between OPN (n = 67) and RAPN (n = 67) groups of patients. Results: The RAPN group had longer operation time (149.0 min vs. 173.3 min, P = 0.030) and longer ischemic time (20.3 min vs. 29.4 min, P = 0.001), but shorter hospital stay (8.2 days vs 6.0 days, P = 0.001) than the OPN group. Estimated blood loss (P = 0.053), pain visual analog score at 1 day postoperatively (P = 0.194), and complications of grade III or higher (P = 0.403) were similar between OPN and RAPN groups. There was no radical conversion or positive surgical margin in either group. Mean change in 6-month estimated glomerular filtration rate was significantly better in the RAPN group (−8.2 vs. −3.1, P = 0.027). There was no statistical difference in recurrence-free survival (P = 0.970) or cancer-specific survival (P = 0.345) between the two groups. Conclusion: RAPN is a safe and feasible surgical modality comparable to OPN for managing renal tumors larger than 4 cm in terms of surgical, functional, and oncological outcomes.

도로 네트워크를 위한 k-최근접 이웃 질의의 처리 방안

이상철,김상욱,Lee, Sang-Cheol,Kim, Sang-Uk 한국통신학회 2008 정보와 통신 Vol.25 No.7

텔레매틱스에서 위치 정보 서비스를 효과적으로 제공하기 위해 이동 객체와 더불어 시설물과 같은 정적 객체에 대한 위치 정보를 효과적으로 관리하는 데이터베이스 기술들이 요구된다 본 논문에서는 도로 네트워크 데이터베이스를 위한 인덱싱 및 질의 처리 기술 현황에 대하여 고찰한다. 텔레매틱스에서는 영역 질의, k-최근접 이웃 질의, 연속 k-최근접 이웃 질의, 공간 조인 질의 등이 발생하며, 이 중 k-최근접 이웃 질의가 빈발하게 발생한다. k-최근접 이웃 질의를 처리하기 위한 효과적인 방안으로 IER, INE, $VN^3$, 근사 인덱싱 기법 등이 있다. 본 논문에서는 각 기법의 개념, 알고리즘, 장단점에 대하여 고찰한다.