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A study on the hydrodynamic coefficients estimation of the 6-DOF model of an underwater vehicle with EKF (확장칼만필터를 이용한 수중운동체의 6자유도 운동을 위한 동유체력계수 추정에 관한 연구)

  • 전창완;박성택;이장규;이동권;최중락;양승윤
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.766-771
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    • 1992
  • The hydrodynamic coefficients estimation problem is important to develop an underwater vehicle and design a controller for it. In this paper, an identification theory, the Extended Kalman Filter, is applied to this parameter estimation problem. In the case that a process noise is not used, all of the parameters are almost exactly converged to the true values respectively. When a process noise is used, all of the parameters are converged to the true values, too, although some parameter estimates are slightly biased. The comparisons of the two trajectories between those generated by the true parameters and those by the estimated parameters show that the parameter estimation problem is well-solved.

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Study on the Algorithm Characteristic of True North-Finding Utilizing 1-axis Gyro Sensor Equipment (1-축 자이로센서를 이용한 진북 추종 알고리즘 특성에 관한 연구)

  • Choi, Ju-Ho;Kwon, Young;Lee, Dae-Chul;Chung, Han-Shik;Jeong, Hyo-Min
    • Journal of Power System Engineering
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    • v.19 no.3
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    • pp.36-41
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    • 2015
  • The true north-finding equipment utilizing gyro sensor is used for INS(Inertial Navigation System) and has an increasing preference for gyro compass system due to compact size, lightening, low power and price. The purpose of this experiment is to research gyro compass system providing high performance in the field of manned or unmanned gyro compass system which proposes the accuracy of 1% utilizing experimented equipment at true north of the earth. Unlike the conventional system, the proposed gyro sensor system indicates to be applied in the various and specific equipment using multiple technique and method.

Design of 5" True Color FED Driving System (5″ FED True Color 구동시스템 설계)

  • Shin, Hong-Jae;Choi, Chang-Woon;Kim, Jin;Choi, Jeong-Og;Kwon, Oh-Kyong
    • Proceedings of the IEEK Conference
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    • 2000.06e
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    • pp.65-68
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    • 2000
  • We design a new driving system of 5" true color FED using current controlled PWM method. Further more, we successfully developed a 5" FED panel, which resolution is 320$\times$240(Color). When we design a 5" FED driving circuit, FED tips are modeled as R-C for circuit simulator of FED driving circuit. In Video data processing, parallel R, G, B input signals is processed independently, so duty ratio increase and no noise, high quality performance is achieved in display of 5" FED. The luminance is about 100cd/$m^2$, the anode power consumption Is 2.1W and total power of the driving system is 21.54W

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THE TRUE METABOLIZABLE ENERGY VALUES OF SOME SELECTED FEEDSTUFFS OF BANGLADESH

  • Huque, Q.M.E.;Kosaka, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.5
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    • pp.571-575
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    • 1996
  • An experiment was conducted to measure the true metabolizable energy (TME) values of seven major poultry feed ingredients, two feed concentrates and one randomly collected layer mixed feed prepared from the available feed ingredients. The results of this study were the most thorough evaluation of the TME content of some selected common feed ingredients of Bangladesh. The observed TME values of some feed ingredients were very close to the values of different origins of feed ingredients. But the TME values measured in mixed layer feed were very low which could not support the standard requirement of laying birds. There values will be of assistance in describing the energy content of the most common available feed ingredients of Bangladesh.

A Rare Case of Spontaneous True Aneurysm of the Occipital Artery

  • Kim, Hyung-Seok;Son, Byung-Chul;Lee, Sang-Won;Kim, Il-Sup
    • Journal of Korean Neurosurgical Society
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    • v.47 no.4
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    • pp.310-312
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    • 2010
  • A 51-year-old man presented with a pulsatile scalp mass over the right occipital region, which had increased in size over the previous 1 month. He had no previous history of head trauma. Three-dimensional computed tomography (3D-CT) angiography of the brain revealed a $3.0{\times}1.5\;cm$ occipital artery aneurysm arising from the occipital artery. The occipital artery aneurysm was removed following the ligation of the proximal and distal portion of the occipital artery aneurysm. The histological diagnosis was true aneurysm. To the best of our knowledge, this is the first reported case in the literature.

True Three-Dimensional Cone-Beam Reconstruction (TTCR) Algorithm - Transform Method from Parallel-beam (TTR) Algorithm - (원추형 주사 방식의 3차원 영상 재구성(TTCR) 알고리즘 - 평행주사 방식(TTR) 알고리즘의 좌표변환 -)

  • Lee, S.Z.;Ra, J.B.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1989 no.05
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    • pp.55-59
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    • 1989
  • A true three-dimensional cone-beam reconstruction (TTCR) algorithm for the complete sphere geometry is derived, which is applicable to the direct volume image reconstruction from 2-D cone-beam projections. The algorithm is based on the modified filtered backprojection technique which uses a set of 2-D space-invariant filters and is derived from the previously developed parallel-beam true three-dimensional reconstruction(TTR) algorithm. The proposed algorithm proved to be superior in spatial resolution compared with the parallel-beam TTR algorithm.

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Cor Triatrium; A Classic Type and a Type Combibed with Atrial Septal Defect; Report of Two Cases (삼심방증 치험 2례)

  • 손제문
    • Journal of Chest Surgery
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    • v.26 no.7
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    • pp.543-547
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    • 1993
  • Cor triatriatum is a rare entity of congenital heart disease characterized by the presence of a fibrousmuscular diaphragm that subdivides the left atrium into a proximal or "accessory" chamber and a distal or "true" left atrial chamber. In the other hand, cor triatriatum is a variant of abnormal connection between the pulmonary vein and true left atrium which is separated from accessory left atrium receiving pulmonary venous blood flow by fibromuscular diaphragm. We experienced two cases of cor triatriatum. One of them was classical, and the other case was combined with atrial septal defect and all pulmonary veins were drained into the " common pulmonary venous chamber " which connected with right atrium and there was no direct communication between the accessory chamber and true left atrium. The abnormal diaphragms were excised and the atrial septal defect was repaired with pericardial patch in case II. The postoperative courses were not eventful and the patients were discharged with good result, and have been in good condition upto now.n good condition upto now.

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Effects of the Grinding Conditions on the Machining Elasticity Parameter

  • Kim, Kang
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.3
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    • pp.62-67
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    • 2003
  • The grinding force generated during the grinding process causes an elastic deformation of the workpiece, grinding wheel, and machine system. Thus, the true depth of cut is always smaller than the apparent depth of cut. This is known as machining elasticity phenomenon. The machining elasticity parameter is defined as a ratio between the true depth of cut and the apparent depth of cut. It is an important factor to understand the material removal mechanism of the grinding process. To increase productivity, the value of this machining elasticity parameter must be large. Therefore, it is essential to know the characteristics of this parameter. The objective of this research is to study the effect of the major grinding conditions, such as table speed, depth of cut, on this parameter experimentally, Through this research, it is found that this parameter value is increasing when the table speed is decreasing or the depth of cut is increasing. Also, this parameter value depends on the grinding mode (up grinding, down grinding).

Surgical Management of the Chronic Dissecting Aneurysm of Ascending Aorta with Aortic Regurgitation (만성 해리성 대동맥류 환자에서의 Bentall 씨 수술적응진성 및 가성 내강 동시 혈류공급술)

  • 강면식
    • Journal of Chest Surgery
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    • v.21 no.1
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    • pp.184-190
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    • 1988
  • The treatment of aortic aneurysm of ascending aorta has been fraught with difficult surgical problems. For the most part, these were resolved in 1968 with the introduction of a technique of total replacement of ascending aorta and reimplantation of the coronary arteries by Bentall and De Bono. This technique however, with all of its advantages, caries a certain problems. In chronic dissecting aneurysms, there is frequently a marked disparity in circumference between the true and false lumen distally. Distal perfusion is directed into both the true and false lumens by removing segment of the septum between the two lumens and constructing the distal graft anastomosis is to the outer layer of aortic adventitia. The distal false lumen, aortic branches and fenestrations have matured and healed in most cases. And importantly, major aortic tributaries may be solely dependent on the false lumen for perfusion. We are presenting two cases of chronic dissecting aneurysm of ascending aorta with aortic regurgitation, who have good result by surgical correction of so-called Bentall procedure with maintenance of blood flow directed into both true and false lumen.

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Synthetic hit-miss transform for optical recognition of a moving target (이동물체의 광학적 인식을 위한 합성 HMT)

  • 김종찬;김정우;이하운;도양회;김수중
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.3
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    • pp.82-90
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    • 1998
  • A hit-miss transform(HMT) using synthetic structuring elements(SE's) for optical recognition of a moving target is proposed. A moving target which was obtained from a fixed view point has objects. In proposed HMT, SE's are synthesized by using SDF(synthetic discriminant function) algorithm for efficient recognitionof various shapes of true class objects in noisy and cluttered scene. The synthetic hit SE and the synthetic miss SE are composed of SDF of hit SE's and miss SE's for each true class object. Simulation results show the proposed method can be used for the recognition of various shapes of the true class with one one HMT operation.

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