인슐린의존형 당뇨병환자에서 임신중 병발한 당뇨병성 케톤산증 1예

이성근,신영구,이성규,정윤석,이관우,김현만,김행수 아주대학교 1997 아주의학 Vol.2 No.2

저자등은 인슐린의존형 당뇨병환자에서 임신중에 병발한 당뇨병성 케톤산증을 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. IDDM is an autoimmune disease resulted from beta cell destruction and insulin deficiency, and developed mostly in children and puberty. Ketoaddosis remains one of the most senous complications that can occur in the pregnant diabetic. A 26-year-old woman, gravida 1, para 0, was admitted at 32 weeks gestation because of fever lasted for 6 days. She had been treated with insulin pump during the pregnancy. Blood sugar was well controlled before admission, and the etiology of her ketoacidosis was urinary tract infection and no insulin-intake. DKA was treated with fluids and intravenous insulin. Urinary tract infection was treated with antibiotics, based on culture test. Healthy newbom was later delivered by cesarean section due to fetal distress. We experienced a case of DKA in pregnant woman and report it with a review on literature.

Coupled Motion Simulation of the Mobile Harbor and Anti-Rolling Devices in Waves

Hyeon-Kyu Yoon,Joo-Nyun Kang,Jae-Moon Lew,Seok-Joon Moon,Tae-Young Chung 한국항해항만학회 2010 한국항해항만학회지 Vol.34 No.4

The Mobile Harbor(MH) is a new transportation platform that can load and unload containers to and from very large container ships in the sea. This loading and unloading by crane can be performed with only very small movements of the MH in waves because MH is operated outside of the harbor. For this reason, an anti-rolling tank(ART) and an active mass driving system(AMD) were designed to reduce MH’s roll motion, especially at the natural frequency of MH. In the conceptual design stage, it is difficult to confirm the design result of theses anti-rolling devices without modeling and simulation tools. Therefore, the coupled MH and anti-rolling devices’ dynamic equations in waves were derived and a simulation program that can analyze the roll reduction performance in various conditions, such as sea state, wave direction, and so on, was developed. The coupled equations are constructed as an eight degrees of freedom (DOF) motion that consists of MH’s six DOF dynamics and the ART's and AMD’s control variables. In order to conveniently include the ART’s and AMD’s control dynamics in the time domain, MH’s radiated wave force was described by an impulse response function derived by the damping coefficient obtained in the frequency domain, and wave exciting forces such as Froude-Krylov force and diffraction force and nonlinear buoyancy were calculated at every simulation time interval. Finally, the roll reduction performances of the designed anti-rolling devices were successfully assessed in the various loading and wave conditions by using a developed simulation program.

Coupled Dynamic Simulation of a Tug-Towline-Towed Barge based on the Multiple Element Model of Towline

Hyeon Kyu Yoon,Yeon Gyu Kim 한국항해항만학회 2012 한국항해항만학회지 Vol.36 No.9

Recently, tug boats are widely used for towing a barge which transports building materials, a large block of a ship, offshore crane, and so on. In order to simulate the dynamics of the coupled towing system correctly, the dynamics of the towline should be well modeled. In this paper, the towline was modeled as the multiple finite elements, and each element was assumed as a rigid cylinder which moves in five degrees of freedom except roll. The external tension and its moment acting on each element of the towline were modeled depending on the position vector’s direction. Tugboat’s motion was simulated in six degrees of freedom where wave and current effects were included, and towed barge was assumed to move in the horizontal plane only. In order to confirm the mathematical models of the coupled towing systems, standard maneuvering trials such as course changing maneuver, turning circle test and zig-zag test were simulated. In addition, the same trials were simulated when the external disturbances like wave and current exist. As the result, it is supposed that the results might be qualitatively reasonable.

Coupled Dynamic Simulation of a Tug-Towline-Towed Barge based on the Multiple Element Model of Towline

Yoon, Hyeon Kyu,Kim, Yeon Gyu Korean Institute of Navigation and Port Research 2012 한국항해항만학회지 Vol.36 No.9

Recently, tug boats are widely used for towing a barge which transports building materials, a large block of a ship, offshore crane, and so on. In order to simulate the dynamics of the coupled towing system correctly, the dynamics of the towline should be well modeled. In this paper, the towline was modeled as the multiple finite elements, and each element was assumed as a rigid cylinder which moves in five degrees of freedom except roll. The external tension and its moment acting on each element of the towline were modeled depending on the position vector's direction. Tugboat's motion was simulated in six degrees of freedom where wave and current effects were included, and towed barge was assumed to move in the horizontal plane only. In order to confirm the mathematical models of the coupled towing systems, standard maneuvering trials such as course changing maneuver, turning circle test and zig-zag test were simulated. In addition, the same trials were simulated when the external disturbances like wave and current exist. As the result, it is supposed that the results might be qualitatively reasonable.

Predictive Control for a Fin Stabilizer

Hyeon-Kyu Yoon,Gyeong-Joong Lee,Tae-Hyun Fang 한국항해항만학회 2007 한국항해항만학회지 Vol.31 No.7

A predictive controller am solve a control problem related to a disturbance-dominant system such as roll stabilization of a ship in waves. In this paper, a predictive controller is developed for a fin stabilizer. Future wave-induced moment is modeled simply using two typical regular wave components for which six parameters are identified by the recursive Fourier transform and the least squares method using the past time series of the roll motion After predicting the future wave-induced moment, optimal control theory is applied to discover the most effective command fin angle that will stabilize the roll motion In the results, wave prediction performance is investigated, and the effectiveness of the predictive controller is compared to a conventional PD controller.

Coupled Motion Simulation of the Mobile Harbor and Anti-Rolling Devices in Waves

Yoon, Hyeon-Kyu,Kang, Joo-Nyun,Lew, Jae-Moon,Moon, Seok-Joon,Chung, Tae-Young Korean Institute of Navigation and Port Research 2010 한국항해항만학회지 Vol.34 No.4

The Mobile Harbor(MH) is a new transportation platform that can load and unload containers to and from very large container ships in the sea. This loading and unloading by crane can be performed with only very small movements of the MH in waves because MH is operated outside of the harbor. For this reason, an anti-rolling tank(ART) and an active mass driving system(AMD) were designed to reduce MH's roll motion, especially at the natural frequency of MH. In the conceptual design stage, it is difficult to confirm the design result of theses anti-rolling devices without modeling and simulation tools. Therefore, the coupled MH and anti-rolling devices' dynamic equations in waves were derived and a simulation program that can analyze the roll reduction performance in various conditions, such as sea state, wave direction, and so on, was developed. The coupled equations are constructed as an eight degrees of freedom (DOF) motion that consists of MH's six DOF dynamics and the ART's and AMD's control variables. In order to conveniently include the ART's and AMD's control dynamics in the time domain, MH's radiated wave force was described by an impulse response function derived by the damping coefficient obtained in the frequency domain, and wave exciting forces such as Froude-Krylov force and diffraction force and nonlinear buoyancy were calculated at every simulation time interval. Finally, the roll reduction performances of the designed anti-rolling devices were successfully assessed in the various loading and wave conditions by using a developed simulation program.

Planar Motion Mechanism Test of the Mobile Harbor Running in Design Speed in Circulating Water Channel

Hyeon-Kyu Yoon,Joo-Nyun Kang 한국항해항만학회 2010 한국항해항만학회지 Vol.34 No.7

Mobile Harbor (MH) is a new transportation platform that can load and unload containers onto and from very large container ships at sea. It could navigate near harbors where several vessels run, or it could navigate through very narrow channels. In the conceptual design phase when the candidate design changes frequently according to the various performance requirements, it is very expensive and time-consuming to carry out model tests using a large model in a large towing tank and a free-running model test in a large maneuvering basin. In this paper, a new Planar Motion Mechanism(PMM) test in a Circulating Water Channel (CWC) was conducted in order to determine the hydrodynamic coefficients of the MH. To do this, PMM devices including three-component load cells and inertia tare device were designed and manufactured, and various tests of the MH such as static drift test, pure sway test, pure yaw test, and drift-and-yaw combined test were carried out. Using those coefficients, course-keeping stability was analyzed. In addition, the PMM tests results carried out for the same KCS (KRISO container ship) were compared with our results in order to confirm the test validity.

Planar Motion Mechanism Test of the Mobile Harbor Running in Design Speed in Circulating Water Channel

Yoon, Hyeon-Kyu,Kang, Joo-Nyun Korean Institute of Navigation and Port Research 2010 한국항해항만학회지 Vol.34 No.7

Mobile Harbor (MH) is a new transportation platform that can load and unload containers onto and from very large container ships at sea. It could navigate near harbors where several vessels run, or it could navigate through very narrow channels. In the conceptual design phase when the candidate design changes frequently according to the various performance requirements, it is very expensive and time-consuming to carry out model tests using a large model in a large towing tank and a free-running model test in a large maneuvering basin. In this paper, a new Planar Motion Mechanism(PMM) test in a Circulating Water Channel (CWC) was conducted in order to determine the hydrodynamic coefficients of the MH. To do this, PMM devices including three-component load cells and inertia tare device were designed and manufactured, and various tests of the MH such as static drift test, pure sway test, pure yaw test, and drift-and-yaw combined test were carried out. Using those coefficients, course-keeping stability was analyzed. In addition, the PMM tests results carried out for the same KCS (KRISO container ship) were compared with our results in order to confirm the test validity.

Causal Analysis of a Tugboat Capsizing Accident in Rough Weather Condition Based on a Dynamical Simulation

Yoon, Hyeon-Kyu,Kim, Sun-Young,Lee, Gyeong-Joong Korean Society of Ocean Engineers 2011 International journal of ocean system engineering Vol.1 No.4

Tugboats are widely used near harbors to assist with various operations such as the berthing and deberthing of very large vessels and the towing of barges. Capsizing accidents involving tugboats occasionally take place when the tugboat makes rapid turns in harsh weather conditions. When there is little evidence suggesting how the accident occurred and when the crew members are missing, it is necessary to predict the time history of the towing vessel’s attitude and trajectory from its departure point to when and where it capsized, depending on various input parameters using a numerical simulation. In this paper, the dynamics of a tugboat and a towed barge in conjunction with the external force and moment were established, and the possible input parameters and operational scenarios which might influence the large roll motion of the tugboat were identified. As a result of analyzing the simulated time history of the excessive roll motion of the tugboat, it was found that roll motion can take place when the tugboat is situated on the crest of a wave and when it is pulled by a towed barge through a towing line. The main cause of the accident would be the parameters that primarily influence such situations. These are the wave parameters, course changing scenario, and the amount of tension.

Hardware-In-the-Loop Simulation for Development of Fin Stabilizer

Yoon, Hyeon Kyu,Lee, Gyeong Joong Korean Society of Ocean Engineers 2013 International journal of ocean system engineering Vol.3 No.1

A ship cruising in the ocean oscillates continuously due to wave action. In order to reduce the ship's roll, we developed a fin stabilizer as an anti-rolling device for a 500-ton-class high-speed marine vessel. During the development phase, it was necessary to set up control gains for the motion and hydraulic systems and assess the effectiveness of the anti-rolling performance on the ground. For this reason, a Target Simulator, which simulated the ship's motion, was given operator inputs such as the engine telegraph and waterjet deflection angle, and generated roll using a one-degree-of-freedom motion base. Hardware-In-the-Loop Simulation (HILS) was performed using the Target Simulator in order to confirm the various logics of the developed fin stabilizer, select initial control gains, and estimate the anti-rolling performance. In conclusion, it was confirmed that HILS was very helpful to develop the fin stabilizer because it could reduce the number of sea trial tests that were needed and could find many malfunctions in the factory a priori.