2-Thienyl chalcone 유도체에 대한 Thioglycolic acid의 친핵성 첨가반응 연구

공승대,황성규,이기창,최상회,오세영 明知大學校 産業技術硏究所 1994 産業技術硏究所論文集 Vol.13 No.-

The Addition reaction kinetics of 2-Thienyl chalone derivatives[][] was investigated by ultraviolet spectrophotometery in 20% dioxane-H2O at 25. The structure of these compounds were ascertained by means of ultraviolet, melting point,IR and NMR spectra. The final product was 2-thienyl chalcone-thioglycolic acid synthesized by the addition of thioglycolic acid for the 2-thienyl chalcone. The rate equations which were applied over a wide pH range(pH 1.013.0) were obtained. The substituent effects on 2-thienyl chalcone derivatives[][] were studied, and the addition reaction were facilitated by electron attracting groups. On the basis of the rate equation and substitutent effect and general base effect,the plausible addition reaction mechanism was proposed : Below pH 9.0, neutral H2O molecule and thioglycolic acid anion competitively attacked on the double bond. Above pH 9.0, It was proportional to concentration of hydroxideion.

마이크로에멀젼 형성에 미치는 알코올과 기름의 영향 : Sodium carboxylate/pentanol/oil/water system

김명자,최승귀 淑明女子大學校 1988 論文集 Vol.29 No.-

The behavior of microemulsions formed with fatty acid soap, medium chain length alcohol, hydrocarbon, and water was studied as a function of alkyl chain length of surfactant, alcohol, and oil, and also as a function of the positional isomer of alcohol, in order to test chain length compatibility effect in microemulsion formation. In the present study, the properties of the microemulsions were investigated by phase diagrams which were obtained by titration method, and also by electrical resistance, viscosity, and surface tension measurements performed throughout the course of microemulsion formation and solubilization. For 1-pentanol as cosurfactant, water solubilization reached a maximum when the oil chain length plus that of alcohol was equal to that of the surfactant, and this result suggested the validity of alkyl chain compatibility effect in microemulsion formation. Maximum solubilization of water decr ased as the position of hydroxyl group in pentanol varied from 1- to 3- pentanol, and alkyl chain compatibility was not observed in the case of 2- and 3- pentanol. Given these facts, nature and mechanism of microemulsion formation were proposed to give some insight into its application to cosmetics.

퍼지 논리 보상기를 포함한 PID 제어기의 Deadzone 시스템 제어

박재형,김승철,최부귀 東亞大學校 附設 情報通信硏究所 1998 情報通信硏究所論文誌 Vol.6 No.1

Simple conventional control methods, such as PD and PID controllers are widely used in industrial applications. Such controllers exhibit poor performance when applied to systems containing nonlinearities arising from unknown deadzones. In this paper, we propose a novel fuzzy based precompensation approach for controlling systems with deadzones. The control structure consists of fuzzy logic based compensator followed by a conventional PID controller. Our proposed control scheme shows superior transient and steady-state performance compared to conventional PD and PID controller. In addition the scheme is robust to variations in deadzone nonlinearities as well as the steady-state gain of the plant. We illustrate the effectiveness of our scheme using computer simulation examples.

한계 입력 내에서 단축 경로를 갖는 로봇 매니퓰레이터의 퍼지 강인 제어기의 설계

박재형,김승철,최부귀 東亞大學校 附設 情報通信硏究所 1999 情報通信硏究所論文誌 Vol.7 No.1

불확실한 모델과 외란을 가진 로봇 매니퓰레이터를 제어하기 위해, 비선형 강인 제어기가 적합하다. 본 논문에서는 불확실한 로못 매니퓰레이터의 제어에 강인 제어기를 적용할 때 발생하는 입력 토크의 포화를 해결하기 위한 알고리즘을 제안한다. 이 알고리즘은 퍼지 논리를 이용하여 초기의 경로를 바탕으로 새로 생성된 단축 경로를 생성하는 것이다. Robot manipulators are operated under model uncertaily, and their dynamics are highly nonlinear. To control them, nonlinear robust controllers are appropriate, but they need high torques so that actuators such as acuating motors can face torque saturation. In this paper, a new scheme is presented to achieve fast tracking in the presence of torque saturation. The scheme generates a new reduced path based onthe initial desired path using a fuzzy logic. Numerical examples are shown to validate the proposed controller using an uncertain two degree-of-freedom underwater robot manipulator.

The Korean Society of Gastroenterology& SLDDS 2051 : Slide Session ; K-MO-01 : GI Motility ; New Bolus Transit Parameter in High-Resolution Impedance Manometry: Correlation with Radionuclide Esophageal Transit Scintigraphy

( Kwi-Sook Choi ),( Segyeong Joo ),( Hwoon-Yong Jung ),( Seung-Jae Myung ),( Kee Wook Jung ),( Ho June Song ),( Seon-Ok Kim ),( Hye Ok Kim ),( So Young Seo ),( Jae Seung Kim ),( Ji Yong Ahn ),( Jeong 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: High-resolution Impedance Manometry (HRIM) is used to detect complete versus incomplete bolus transit. Three-Dimensional Volume of Inverted Impedance (VII) was developed to measure the remnant impedance volume between each swallow. However, its clinical usefulness and meaning were not fully evaluated. Radionuclide esophageal transit scintigraphy (RETS) has been used to determine bolus transit in esophageal motor disorders. Here we aimed to investigate the absolute measurement of bolus transit based on the 3-D volume of impedance and its clinical meaning by assessing its relationship with RETS. Methods: Thirty-one patients who underwent both HRIM and RETS were enrolled in this study. Twenty-nine of these patients were diagnosed with achalasia and two patients were normal. Each patient underwent HRIM using a catheter with 32 circumferential pressure and 16 impedance sensors. The impedance profi les were converted to ASCII fi les and analyzed with the MATLAB program. VII was plotted after transforming the data to a cubic spline interpolation followed by resampling the manometry position at 0.2-cm intervals. The VII between swallows was categorized into four different 5-second frames. RETS was performed by using 99mTc-DTPA, and remnant radionuclide in the lumen of esophageal body was measured at 1,5,10,15,and 20 minutes ofinterval after swallowing. Results: A total of 40 HRIM and RETS procedures were analyzed (nine patients with achalasia underwent both tests twice before and after treatment). The mean VII value of the later 15 second frames from each swallow showed a signifi cant positive correlation to the 20-minute RETS (r=0.31, P=0.04). Moreover, the mean VII value of the later 10-second frames also showed a signifi cant positive correlation to 20-minute RETS (r=0.32, P=0.04). Conclusions: The newly developed VII method may have a close relationship with the currently using RETS despite different protocols.

ABSTRACTS ; Posters : Quantitative Analysis of Inositol Phosphatides by Gas Chromatography and Its Application for Enzyme Research

Kwi Deok Park,Jin Sung Choi,Hyo Joon Kim,Key Seung Cho 한국생화학분자생물학회 (구 한국생화학회) 1995 추계학술대회집 Vol.- No.-

Antiviral Activity of Yogurt against Enterovirus 71 in Vero Cells

Choi, Hwa-Jung,Song, Jae-Hyoung,Park, Kwi-Sung,Baek, Seung-Hwa,Lee, Eun-Sook,Kwon, Dur-Han 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

Five yogurts were fermented with each bacteria strain. The viability and pH of each yogurt during fermentation or storage were evaluated, and then the cytotoxicity and antiviral activity against enterovirus (EV) 71 of cell-free supernatants (CFS) of the metabolites of each yogurt were compared with those of de Man, Rogosa, and Sharpe (MRS) broth fermented with the same bacteria. As the results, the number of viable bacteria for each yogurt after fermentation or during storage always remained higher than 5 log CFU/mL and the pH of those ranged from 4 to 6. The CFS of all yogurts showed antiviral activity over 45% against EV71, while it didn't exhibit cytotoxicity in Vero cells. Specially, the CFS of yogurt fermented with Lactobacillus plantarum and Bifidobacterium bifidum exhibited high anti-EV71 activity of 92.74 and 90.44%, respectively. In contrast, the CFS of each MRS broth fermented with the same bacteria showed low antiviral activity of less than 30%.

Clinical Course of the Benign Prostate Hyplasia Patients during the Intermittent Use of 5-Alpha Reductase Inhibitors

Kwi Bok Choi,Byounghoon Kim,In-Chang Cho,Seung Ki Min 대한요로생식기감염학회 2019 Urogenital Tract Infection Vol.14 No.3

Purpose: 5-Alpha reductase inhibitors (5ARI), inhibit the conversion of testosterone to dihydrotestosterone, which is essential in prostate hyperplasia, and decreases the prostate volume directly. On the other hand, 5ARI have a range of side effects, such as sexual dysfunction. After the discontinuation of 5ARI, prostate regrowth occurs rapidly until it reaches the baseline size. This study examined the effects of 5ARI when used intermittently.Materials and Methods: Between March 2009 and May 2017, patients who visited one physician’s outpatient clinic and were diagnosed with BPH underwent transrectal ultrasonography. The selected patients began to take 5ARI until the prostate size decreased at least 10% of the baseline (the first medication). After confirming adequate prostate shrinkage, the patients stopped medication until prostate regrowth reached 50% of the decreased size. After regrowth, they restarted medication for one year (second medication). The prostate size, serum prostate specific antigen (PSA) levels, international prostate symptom score (IPSS) scores, and maximum flow rate (Qmax) in uroflowmetry were collected after the first and second medication and compared using paired t-tests.Results: Sixty patients with a mean age of 65.1 years were included in the study. The prostate size and serum PSA level increased after the second medication compared to the first, and the prostate reduction and Qmax in uroflowmetry decreased significantly. On the other hand, the symptoms felt by the patients surveyed by the IPSS scores showed no significant difference.Conclusions: 5ARI appear to be less effective in reducing the prostate volume and improving uroflowmetry after discontinuation.

Analysis of Trends of 3 Major Benign Prostatic Hyperplasia Surgery in the Last 5 Years

Seung Ki Min(민승기),Byoung Hoon Kim(김병훈),Kwi Bok Choi(최귀복),In-Chang Cho(조인창) 대한비뇨기종양학회 2019 대한비뇨기종양학회지 Vol.17 No.3

Purpose: The goal of this study is to analyze the trends in surgical management of Benign prostatic hyperplasia (BPH) in Korea during the last 5 years from 2014 to 2018. Materials and Methods: We retrieved the medical statistics associated with the Healthcare Big Data Opening System available online. We analyzed the number of cases after 2014 for transurethral resection of prostate (TURP), photoselective vaporization of the prostate (PVP), and holmium laser enucleation of the prostate (HoLEP), respectively. We then analyzed and charted the cases according to the number of patients hospitalized or treated as outpatients, depending on age group, type of medical institutions, and the location of medical institutions. Results: The number of patients with BPH has increased steadily. The number of TURP and HoLEP procedures steadily increased, while the number of PVP interventions decreased dramatically. The number of HoLEP cases increased by 22% from 2014 to 2018, which is the fastest rate among the three surgeries. In addition, the number of patients aged 75 years or older as well as the proportion of inpatient surgeries compared with outpatient treatments has increased. The number of cases undergoing TURP increased rapidly in general hospital and those treated with HoLEP increased in the general and tertiary referral hospitals. Conclusions: Interventions using TURP and HoLEP has increased, and the age of patients undergoing surgery has increased gradually. Cases treated with TURP and HoLEP in general and tertiary referral hospitals showed an increasing trend from the metropolitan area to the province.

The Design of Adaptive Fuzzy Controller for Vibration Suppression

Seung-Cheol Kim,Jae-Hoon Sul,Jae-Hyung Park,Young-Do Lim,Boo-Kwi Choi 제어로봇시스템학회 2001 제어로봇시스템학회 국제학술대회 논문집 Vol.2001 No.10