• Title/Summary/Keyword: Main Axis

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Echocardiograpyhic Assessment and Clinical Application of Cardiac Disease in Korea Jin-do Dog III. Detection of Heartworm (진돗개에서 심장초음파 측정치와 평가와 임상적 응용)

  • 박인철;강병규;손창호
    • Journal of Veterinary Clinics
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    • v.17 no.1
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    • pp.194-204
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    • 2000
  • Echocardiography was performed to obtain the optimal planes for diagnosis of canine heartworm disease in 11 dogs. Imaging planes were taken the left ventricular outflow tract long-axis view, 4-chamber long-axis view, chordae tendineae level short-axis view and modified pulmonary arteries level short-axis view in the right parasternal window, and aptical 4-chamber long-axis view in hte left parasternal window. After echocaridography, the pulmonary artery valve pat was ligated with double 1-0 silk under the general anesthesia to prevent heartworm moving from pulmonary artery to right ventricle. The dogs were euthanized and examained for heartworms in heart and great vessels. Many adult heartworms were identified ultrasonographically within main pulmonary artery, bifurcation of pulmonary artery and right pulmonary artery, but not identified within right ventricle and atrium. At necropsy, adult heartworms were mainly found in pulmonary artery in 11 days, and also found in right ventricular outflow tract and right ventricle in 2 of 11 dogs. The modified pulmonary arteries level short-axis view was the best imaging plane for identifiying heartworms because the main pulmonary artery, branches of pulmonary artery and right pulmonary artery could be showed. The aortic root internal dimension (AOID) and right pulmonary atery internal dimension (RPAID) were measured from the modified pulmonary ateries level short-axis view and left ventricular outflow tract long-axis view. The RPAID and RPAID/AOID was higher in heartworm infected dogs than normal Korea Jin-do dogs in modified pulmonary arteries level short-axis view, and the AOID, RPAID and RPIAID/AOID was higher than in left ventricular outflow tract long-axis view, respectively. These results indicate that the pulmonary arteries were the major habitat of adult heartworm in canine heartworm disease and the modified pulmonary arteries level short-axis view was the best imaging planes for identifying heartworms because the main pulmonary arteries could be showed. Therefore the modified pulmonary arteries level short-axis view can be used for diagnosing heartworm disease and for monitoring dilation of pulmonary artery.

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Magnetic Saturation Effect on the Rotor Core of Synchronous Reluctance Motor

  • Kim, Ki-Chan
    • Journal of Electrical Engineering and Technology
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    • v.6 no.5
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    • pp.634-639
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    • 2011
  • This paper presents a study on the design parameters that consider the magnetic saturation effect in a rotor core of a synchronous reluctance motor. Two important design parameters in a rotor are selected to analyze the saturation effect of a synchronous reluctance motor, particularly in a rotor core. The thickness of the main segment, which is the main path of the d-axis flux, and the end rip, which affects the q-axis flux, are analyzed using the d-axis and q-axis inductances. Moreover, the characteristics of torque and torque ripple when magnetic saturation takes place are analyzed. The saturation effect is verified by comparing the reluctance torque between the experiment and FEM simulation.

An experimental study on attitude control of spacecraft using roaction wheel (반작용 휠을 이용한 인공위성 지상 자세제어 실험 연구)

  • 한정엽;박영웅;황보한
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1334-1337
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    • 1997
  • A spacecraft attitude control ground hardware simulator development is discussed in the paper. The simulator is called KT/KARI HILSSAT(Hardware-In-the Loop Simulator Single Axis Testbed), and the main structure consists of a single axis bearing and a satellite main body model on the bearing. The single axis tabel as ans experimental hardware simulator that evaluates performance and applicability of a satellite before evolving and/or confirming a mew or and old control logic used in the KOREASAT is developed. Attitude control of spaceraft by using reaction wheel is performed.

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A Study on Air Flow Analysis in Vertical-axis Wind Turbine (수직축 풍력터빈의 유동해석에 관한 연구)

  • Lee, Ki-Seon;Park, Jung-Cheul
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.158-162
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    • 2017
  • This paper did basic study on the vertical-axis wind turbine. Namely, This paper was try to find the optimum conditions by using the ANSYS CFX simulation program through the changes of the main-blade angle and sub-blade angle. Main-blade Shape #4 angle $45^{\circ}$ compared to others Shape angle $0^{\circ}$ was increased by 157.2[%] to 263.2[%] in the power output and was increased by 110[%] to 250[%] in the power coefficient. Also, when the Shape #5 Fin length of main-blade doubles, because the power output was 70.8[%] compared to Shape #1 and 27.5[%] compared to Shape #4, and the power coefficient was 60[%] compared to Shape #1 and 28.6[%] compared to Shape #4, the power output and the power efficiency were rather reduced. The output current of Shape #4 was increased 109.9[%] compared to Shape #1 and increased 250[%] compared to Shape #5, and The output voltage of Shape #4 was increased 22.5[%] compared to Shape #1 and increased 3.7[%] compared to Shape #4.

A Study on Determination of Frontal QRS Electrical Axis by Minnesota Coding Method (MINNESOTA CODE 분류방식에 의한 전면 QRS 전기축 판정에 관한 연구)

  • Park, Dong-Chan;Lee, Myoung-Ho
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.421-425
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    • 1989
  • This paper present a algorithm for determination of the frontal QRS axis. Determination of electrical QRS axis helps In the differential diagnosis of wide QRS tachycardia and of hemiblock and In the localization of an accessory pathway. At first detecting R-point data and S-point data and two data is sumed and this data is determind such as positive or negative. Reference data is calculated by 9-point derivertives that is less affected by noise. Secondly, using data of lead2 calculate a morphology, this value is threshold for executing determination algorithm. This process is main body of this algorithm. As this algorithm have a six pattern of the axis that coded by minnesota ending method, the axis is determined more precisely than any other algorithm using 3 leads and affirm a relation of a axis and hemiblock and tachycardia.

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Geometric Modeling and Five-axis Machining of Tire Master Models

  • Lee, Cheol-Soo
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.3
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    • pp.75-78
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    • 2008
  • Tire molds are manufactured by aluminum casting, direct five-axis machining, and electric discharging machining. Master models made of chemical wood are necessary if aluminum casting is used. They are designed with a three-dimensional computer-aided design system and milled by a five-axis machine. In this paper, a method for generating and machining a tire surface model is proposed and demonstrated. The groove surfaces, which are the main feature of the tire model, are created using a parametric design concept. An automatically programmed tool-like descriptive language is presented to implement the parametric design. Various groove geometries can be created by changing variables. For convenience, groove surfaces and raw cutter location (CL) data are generated in two-dimensional drawing space. The CL data are mapped to the tread surface to obtain five-axis CL data to machine the master model. The proposed method was tested by actual milling using the five-axis control machine. The results demonstrate that the method is useful for manufacturing a tire mold.

Dynamics of a Micro Three-Axis Ring Gyroscope (마이크로 3축 링 자이로스코프의 동역학)

  • Choi, Sang-Hyun;Kim, Chang-Boo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.37-43
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    • 2002
  • In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The equations of motion, the response to angular velocities, and the relationships between the natural modes of vibration are derived and compared with the previous studies for the design of a micro three-axis ring gyroscope.

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Dynamics of a Micro Three-axis Ring Gyroscope (마이크로 3축 링 자이로스코프의 동역학)

  • Kim, Chang-Boo;Choi, Sang-Hyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.12
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    • pp.1001-1009
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    • 2002
  • In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The equations of motion, the response to angular velocities, and the relationships between the natural modes of vibration are derived and compared with the previous studies for the design of a micro three-axis ring gyroscope.

A Study on Active SAR Satellite Maneuver Time Reduction through Sequential Rotation (연속회전을 통한 능동 합성개구레이더위성 기동시간 단축 연구)

  • Son, Jun-Won;Park, Young-Woong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.7
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    • pp.648-656
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    • 2015
  • Active SAR satellite's main maneuver is roll axis maneuver to change SAR antenna direction. In addition, yaw steering is required to minimize the doppler centroid variation. Thus, it is resonable to assign the torque/momentum capacity mostly to roll axis and then yaw axis. In this case, the pitch axis shows low agility performance. However, due to orbit maintenance, large angle maneuver about pitch axis is sometimes required. In this paper, we study the pitch axis maneuver time reduction through sequential rotation about roll and yaw axis. Since these two axes have high agility performance than pitch axis, maneuver time reduction is possible when large angle rotation about pitch axis is required.

KisBot II : New Spherical Robot with Curved Two-pendulum Driving Mechanism (두 개의 곡선형 펜들럼 주행 메커니즘을 갖는 구형로봇)

  • Yoon, Joong-Cheol;Ahn, Sung-Su;Lee, Yun-Jung
    • The Journal of Korea Robotics Society
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    • v.6 no.4
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    • pp.323-333
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    • 2011
  • Due to the limited pendulum motion range, the conventional one-pendulum driven spherical robot has limited driving capability. Especially it can not drive parallel direction with center horizontal axis to which pendulum is attached from stationary state. To overcome the limited driving capability of one-pendulum driven spherical robot, we introduce a spherical robot, called KisBot II, with a new type of curved two-pendulum driving mechanism. A cross-shape frame of the robot is located horizontally in the center of the robot. The main axis of the frame is connected to the outer shell, and each curved pendulum is connected to the end of the other axis of the frame respectively. The main axis and pendulums can rotate 360 degrees inside the sphere orthogonally without interfering with each other, also the two pendulums can rotate identically or independent of each other. Due to this driving mechanism, KisBot II has various motion generation abilities, including a fast steering, turning capability in place and during travelling, and four directions including forward, backward, left, and right from stationary status. Experiments for several motions verify the driving efficiency of the proposed spherical robot.