기능성 소화불량증환자에서 Winstal® 투여에 관한 임상경험

이창형,김영탁,금민수,권중구,안병철,윤영미,권영오,김성국,최용환,정준모 慶北大學校 醫科大學 1994 慶北醫大誌 Vol.35 No.3

목적 : 기능성 소화불량증은 소화, 흡수등 장관의 기능적인 이상과 관련되어 있을 것으로 생각되며 복합소화효소제(Winstal®)를 투여하여 그 임상효과를 평가하고자 본 연구를 실시하였다. 대상 및 방법 : 1994년 3월 부터 6월까지 경북대학교병원 내과를 방문한 기능성 소화불량증을 호소하는 환자 20명을 대상으로 Winstal®을 1회 1정씩, 1일 3회 식후 30분내에 경구로 2주간 투여하였다. 결과 : 소화불량증의 증상은 복부불쾌감, 복부팽만감, 식욕부진 및 오심, 복부동통, 공기연하증, 고창 및 구토순이었으며, 증상의 개선은 복부불쾌감이 76.4%(13/17)로 가장 높았으며, 그 다음으로 복부팽만감 및 공기연하증이 66.5%(10/15, 6/9)이었고, 오심 61.5%(8/13), 식욕부진 53.8%(7/13), 복부동통 41.6%(5/12), 고창 37.5%(3/8)이었다. 각 환자별 종합적인 증상의 개선도는 현저한 개선이 2예(10%), 중등도 개선이 3예(15%), 약간개선이 11예(55%), 불변이 4예(20%)이었으며 종합적인 유효율은 80%(16/20)이었다. 부작용은 한 예에서도 관찰되지 않았다. 결론 : 본 제제는 기능성 소화불량증 환자의 증상개선에 추천할 만한 유효한 약제로 생각된다. Dyspepsia is a common symptom in gastroenterologic practice and trigger for numerous consultations with physician. The treatment of chronic functional dyspesia is unsatisfactory. This study was performed to evaluate the efficacy of the digestive compound (Winstal®) on 20 functional dyspepsia patients. On open trial, all patients were given 6 tablets daily for 2 weeks and we evaluated the efficacy of this preparation according to the degree of the improvement. The improvement of symptoms was 76.4%(13/17) in abdominal discomfort, 66.5%(10/15, 6/9) in abdominal distension and aerophagia, 61.5%(8/13) in nausea, 53.8%(7/13) in abdominal pain, and 37.5% (5/12) in flatulence, respectively. Overall effectiveness of subjective symptoms was 80% (16/20) and there were no untoward effects of the preparations during this study. As a result, We think that this preparation is an effective one to relieve symptoms of functional dyspepsia.

Impact Analysis of Tolerance and Contact Friction on a RV Reducer using FE Method

Hyeong-Joon Ahn,Byeong Min Choi,Young Hwan Lee,팜안덕 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.7

Since RV (rotation vector) reducer has a high reduction ratio with compact size, high efficiency and stiff ness, the reducer is extensively used in applications requiring high precision in the restricted space like industrial robotic joints. Since the cycloid disk of the RV reducer makes contacts with many pin-rollers simultaneously, tolerance and friction between the cycloid disk and the pin-rollers significantly affect the contact force of the cycloid disks as well as the performance of the RV reducer. This paper presents an impact analysis of tolerance and friction on the RV reducer using FE method. A FE model for a two-disk RV reducer and the eccentric shaft is built considering tolerance and friction between the cycloid disk and the pin-rollers. Then, the FE analysis of an ideal rigid cycloid reducer was performed and verified with the theoretical calculation. The effects of tolerance and friction on multi-contact and the output torque of the RV reducer were investigated. Since the contact forces vary according to both tolerance and friction, the resulting torsional rigidity and output torque are affected considerably. Precisely, the tolerance mainly decreases the torsional rigidity while the friction primarily increases the output torque fluctuation.

Three-Phase Coil Configurations for the Radial Suspension of a Bearingless Slice Motor

Hyeong-Joon Ahn,Ngoc Vu Vo,Shenghe Jin 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.1

Demand for energy-saving, high-efficiency motors has been growing due to the accelerating spread of electric cars, increasing focus on energy conservation and environmental protection. One of the main components of an electric motor system, the bearing is not only a source of frictional losses but also typically the first component to fail in an electric motor system. Therefore, non-contact supporting motors have been developed to overcome the shortcomings of mechanical bearings. Although the torque windings for electric motors were well developed in the motor industry, there are only few studies on the suspension coil of the bearingless motor systems. This paper presents a generalized three-phase coil configuration for the radial suspension of a bearingless slice motor. First, the bearingless motor and two windings are introduced. Then, the design problem of a bearingless slice motor's suspension coil for pure sinusoidal magnetomotive force is formulated as a well-known linear algebra problem or Ax = b. Then, the minimal realization of three-phase suspension coil configuration for the bearingless motors with various slots is determined by solving Ax = b. In addition, FE analysis is performed to verify the three-phase suspension coil configuration for bearingless motor with various slot numbers. The normalized suspension force, the normalized resistance, and total harmonic distortion of the suspension winding for various slot numbers are compared.

Poster Session : PS 0042 ; Cardiology : A Case of Simultaneous Anterior and Inferior ST-Segment Elevation Myocardial Infarction Due to Double Coronary Artery Thrombosis

( Joon Ho Ahn ),( Hyeong Won Seo ),( Min Chul Kim ),( Hae Chang Jeong ),( Keun Ho Park ),( Doo Sun Sim ),( Young Joon Hong ),( Ju Han Kim ),( Myung Ho Jeong ),( Young Keun Ahn ) 대한내과학회 2014 대한내과학회 추계학술발표논문집 Vol.2014 No.1

Acute ST-segment elevation myocardial infarction generally results from a plaque rupture with occlusive thrombi formation. However, rare case has simultaneous multiple ST-segment elevation with thrombi and it was known to be associated with fatal clinical course such as sudden cardiac death or cardiogenic shock. The incidence and clinical outcome of this uncommon condition is uncertain. We describe a 46 yearold woman who was found to have simultaneous ST-segment elevation of anterior and inferior wall, and critical thrombotic stenosis of proximal left anterior descending artery and middle right coronary artery by coronary angiogram. The patient was successfully treated by percutaneous coronary intervention with intravascular ultrasound guidance.

Effects of the rotor obliquity on the cylindrical capacitive sensor

Ahn, Hyeong-Joon,Jeon, Soo IOP Pub 2011 Measurement Science and Technology Vol.22 No.4

<P>The cylindrical capacitive sensor (CCS) is superior to conventional probe-type sensors in measuring the radial error motion of a rotor accurately since the CCS is immune to geometric errors of the rotor. However, due to the extended axial length of the CCS, the obliquity (or the axial tilt) of the rotor may cause unnecessary measurement error. This paper presents the effects of rotor obliquity on the performance of the CCS. The existing analytical model for the CCS has been extended to incorporate the axial tilt of the rotor, which leads to a new mathematical model for the CCS that can describe the complete three-dimensional motion of the rotor. Based on the new mathematical model, a nonlinear analysis is performed to derive the analytical solution of the measured rotor displacement with the CCS. As a result, it has been revealed how the rotor obliquity causes measurement errors in both eccentricity and phase angle. The analytical results are compared and verified with simulations.</P>

System Modeling and Robust Control of an AMB Spindle : Part I Modeling and Validation for Robust Control

Ahn, Hyeong-Joon,Han, Dong-Chul The Korean Society of Mechanical Engineers 2003 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.17 No.12

This paper discusses details of modeling and robust control of an AMB (active magnetic bearing) spindle, and part I presents a modeling and validation process of the AMB spindle. There are many components in AMB spindle : electromagnetic actuator, sensor, rotor, power amplifier and digital controller. If each component is carefully modeled and evaluated, the components have tight structured uncertainty bounds and achievable performance of the system increases. However, since some unknown dynamics may exist and the augmented plant could show some discrepancy with the real plant, the validation of the augmented plant is needed through measuring overall frequency responses of the actual plant. In addition, it is necessary to combine several components and identify them with a reduced order model. First, all components of the AMB spindle are carefully modeled and identified based on experimental data, which also render valuable information in quantifying structured uncertainties. Since sensors, power amplifiers and discretization dynamics can be considered as time delay components, such dynamics are combined and identified with a reduced order. Then, frequency responses of the open-loop plant are measured through closed-loop experiments to validate the augmented plant. The whole modeling process gives an accurate nominal model of a low order for the robust control design.

An interface method of a frequency-modulated eddy-current displacement sensor for real-time control

Hyeong-Joon Ahn(안형준),Ngoc Vu Vo(보응옥부) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.4

System Modeling and Robust Control of an AMB Spindle:Part Ⅱ A Robust Controller Design and its Implementation

Hyeong-Joon Ahn,Dong-Chul Han 대한기계학회 2003 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.17 No.12

This paper discusses an entire procedure for a robust controller design and its implementation of an AMB (active magnetic bearing) spindle, which is part Ⅱ of the papers presenting details of system modeling and robust control of an AMB spindle. Since there are various uncertainties in an AMB system and reliability is the most important factor for applications, robust control naturally gains attentions in this field. However. tight evaluations of various uncertainties based on experimental data and appropriate performance weightings for an AMB spindle are still ongoing research topics. In addition, there are few publications on experimental justification of a designed robust controller. In this paper, uncertainties for the AMB spindle are classified and described based on the measurement and identification results of part I, and an appropriate performance weighting scheme for the AMB spindle is developed. Then, a robust control is designed through the mixed μ synthesis based on the validated accurate nominal model of part I, and the robust controller is reduced considering its closed loop performance. The reduced robust controller is implemented and confirmed with measurements of closed-loop responses. The AMB spindle is operated up to 57,600 rpm and performance of the designed controller is compared with a benchmark PID controller through experiments. Experiments show that the robust controller offers higher stiffness and more efficient control of rigid modes than the benchmark PID controller.

Driving an AMB system using a 2D space vector modulation of three-leg voltage source converters

Ahn, Hyeong-Joon,Jeong, Se-Na 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.1

This paper presents new methodologies for driving an active magnetic bearing (AMB) system using a two-dimensional (2D) space vector modulation of three-leg voltage source converters. Two types of driving configurations are proposed: full-performance and economy. The economy configuration is proven to be more cost-effective than the conventional driving configurations. For both driving configurations, conversion rules are developed to calculate the three-leg voltage references from two-coil voltage references of an AMB system. In addition, the potential performance limit of the proposed driving configurations is analyzed. Experimental results are presented using a single degree of freedom (DOF) AMB system to verify the analytical results.

Evaluation and the improvement of the noise of an FM (frequency-modulated) displacement sensor for AMBs

Hyeong-Joon Ahn(안형준),Ngoc Vu Vo(보응옥부) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4