• Title/Summary/Keyword: Bent-axis

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Toxic Effect of Cadmium on the Amphibian Axis Formation (카드뮴이 양서류의 체축 형성에 미치는 독성 효과)

  • 김윤경;정해문
    • Toxicological Research
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    • v.11 no.1
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    • pp.37-42
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    • 1995
  • Effect of cadmium on the early amphibian development was analyzed through FETAX (Frog Embryo Teratogenesis Assay: Xenopus). Embryos manifested concentration-dependent mortality and realformations; shortage of anterior-posterior axis gut realformation, ocular anomalies, bent notochord, misshapen dorsal fin, and derreal blisters. The treatment with 1.5ppm cadmium solution caused 100% mortality and concentration of lppm did not kill the embryos that caused 100% anomaly. The teratogenic index (TI = LC50 /EC50) was 2.8 indicating that $CdCl_2$ is teratogenic for Xenopus laevis. Embryos that were pulsetreated with at early to late blastula stage (St. 3-9) and mid to late blastula stage (St. 6-10) showed relatively strong resistance to cadmium, but the embryos treated at gastrula stage (St. 10-13) showed high mortality. And the embryos treated at tailbud stage (after St. 25) showed highest mortality of any other early stages. Effects of temperature were studied through pulse- treatment during gastrula stage at $20^{\circ}C$ and $30^{\circ}C$. The embryos treated with 7.5ppm at $30^{\circ}C$ and 15ppm at $20^{\circ}C$ caused 100% mortality respectively, indicating that higher temperature had more severe toxic effect. One of the most peculiar effect of cadmium at gastrulation was distortion of the tail. The probable cause of toxic effect of Cd was discussed.

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The Feng-Shui Location and Spatial Composition of Junkyung and Youngkyung Tomb at Samcheok (삼척 준경묘와 영경묘의 풍수적 입지와 공간구성)

  • Choi, Jang-Soon
    • Journal of the Korean Institute of Rural Architecture
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    • v.12 no.2
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    • pp.135-142
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    • 2010
  • This research aims to examine the characteristics of tomb sites including tomb mound and attached buildings and also to find out the principles reflected in the traditional oriental Feng-Shui location and spatial composition of Junkyung and Youngkyung tomb at Samcheok. The results of this study are as follows. These tombs harmonize with each other in the cosmic dual forces because Junkyung tomb is men's sex symbol and tiger to lie on his belly and Youngkyung tomb is women's sex symbol in geographical feature. Spatial structure in these tomb sites were placed in a reflected line following the hierarchy of metaphysics by standing high Geumchunkyo(Bridge)-Hongsalmun(Gate)-Jegak(Pavilion)-Bongbun(Tomb mound). Axis structure of these tombs is irregular bent-axis type from Geumchunkyo to Bongbun, specially in case of Youngkyung tomb it is getting more refractive. These tombs are divided into and characterized by three zones. Firstly the space for living people constitutes from Geumchunkyo to Hongsalmun, secondly the semi-sacred space constitutes from Hongsalmun to Jegak, and lastly the space for the dead constitutes from the back of Jegak to Bongbun. - type Jegak instead of T type Jegak generally used at Chosun Dynasty was installed because of claypan stretched out in front of Junkyung tomb and Bongbun of Youngkyung tomb located at a ravine between two mountain ranges.

A study on the real time inspection algorithm of FIC device in chip mounter (칩 마운터에의 FIC 부품 인식을 위한 실시간 처리 알고리듬에 관한 연구)

  • Ryu, Gyung;Kim, Young-Gi;Moon, Yoon-Sik;Park, Gui-Tae;Kim, Gyung-Min
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.48-51
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    • 1997
  • This paper presents the algorithm of FIC inspection in chip mounter. When device is mounted on the PCB, it is impossible to get zero defects since there are many problems which can not be predicted. Of these problems, devices with bent corner leads due to mis-handling and which are not placed at a given point measured along the axis are principal problem in SMT(Surface Mounting Technology). In this paper, we proposed a new algorithm based on the Radon transform which uses a projection to inspect the FIC(Flat Integrated Circuit) device and compared this method with other algorithms. We measured the position error and applied this algorithm to our image processing board which is characterized by line scan camera. We compared speed and accuracy in our board.

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The Study on Development of Fixed Displacement Piston Pump for Special Access Vehicle (특수 차량용 정용량 피스톤 펌프의 개발에 관한 연구)

  • Park, Jeong-Ho;Kim, Moon-Kyung;Choi, Suk-Chang
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.3
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    • pp.19-27
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    • 2010
  • Cylinder block is driven by tapered piston for bent-axis type piston pump, so that geometrical mechanism is very complicate. Piston rod must have not separated from shaft when shaft and piston rod is assembled. For this reason, shaft design is changed. Finite element analysis is performed for analyzed structural stability and flexible dynamic behavior. The result of the analysis, maximum equivalent stress occurred under yield stress, therefore structural stability is satisfactory. and flexible dynamic analysis give useful information about driving gear. These background data is avail of manufacture of piston pump.

Friction Characteristics between the Cylinder Block and the Spherical Valve Plate in Hydraulic Axial Piston Pump (유압 액셜 피스톤 펌프에서 실린더 블록과 구면 밸브 플레이트 사이의 마찰 특성)

  • 김종기;오석형;정재연
    • Tribology and Lubricants
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    • v.14 no.4
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    • pp.23-28
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    • 1998
  • To increase the efficiency of the hydraulic axial piston pumps, it is need to know the various characteristics in the sliding contact parts of them. Especially, friction characteristics between the cylinder block and the valve plate in the hydraulic axial piston pumps plays an important role to high power density. In this paper, we tried to clarify friction characteristics between the cylinder block and the spherical valve plate in bent-axis-type axial piston pump in experimentally. Results are arranged as follow; (1) friction torque between the cylinder block and the spherical valve plate has a proportional relation to weight or rotational speed, and is strongly affected by temperature. (2) Friction torque strongly depends on force balance ratio in valve plate. (3) In this experiment, lubrication condition between the cylinder block and the spherical valve plate is under hydrodynamic lubrication.

Friction characteristics between the cylinder block and the valve plate in axial piston pump (액셜 피스톤 펌프에서 실린더 블록과 밸브 플레이트 사이의 마찰 특성)

  • 김종기;정재연
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.04a
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    • pp.249-255
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    • 1998
  • To increase the efficiency of the hydraulic axial piston pumps, we have to know the various characteristics in the sliding parts of them. Especially, friction characteristics between the cylinder block and the valve plate in the hydraulic axial piston pumps plays an important role to high power density. In this paper, we tried to clarify friction characteristics between the cylinder block and the spherical valve plate in bent-axis-type axial piston pump by using of modeling experiment. The main results of this study are these; (1) Friction torque between the cylinder block and the spherical valve plate has a proportional relation to weight or rotational speed, and is strongly affected by temperature. (2) Friction torque strongly depends on force balance ratio. (3) In this experiment, lubrication condition between the cylinder block and the spherical valve plate is under hydrodynamic lubrication.

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Control of Bent Axis Inclination Pistion Motor for Application Continuously Variable Transmission System (휠 타입 굴삭기의 무단변속시스템 적용을 위한 액시얼 사축식 피스톤 모터의 제어)

  • 이성민;장성욱;박명관;이진걸
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.463-467
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    • 2003
  • The traveling system of wheel type excavator, that is applied to drive method by friction of transmission, has many problems about transmisson. It need to settle the problem which is occurred at wheel type excavator and to study continuously variable transmisson which is used with only travel motor. This paper base on mathmetical modeling for travel motor and travel motor of wheel type excavator is designed continuously variable transmisson system without transmisson by direct control method.

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A Kinematic Analysis on Piston Rod Mechanism in Swashplate Type Hydraulic Axial Piston Motor/Pump Using Constant Velocity Joint (등속조인트를 적용한 사판식 유압 모터/점프의 로드형 피스톤에 대한 운동해석)

  • Kim K.H.;Kim S.D.;Ham Y.B.;Lee J.C.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.2 no.1
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    • pp.1-8
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    • 2005
  • Recently, swash plate type hydraulic axial piston motors/pumps are being extensively used in the world, because of simple design, light weight and effective cost. Structural problem of the swash plate type motor/pump is that tilting angle of swash plate should be limited to relatively small value and lateral farce on pistons has an undesirable effect in reciprocating motion. To solve these problems, piston rod mechanism, which is commonly used in bent axis type motor/pump, is considered to be applied to the swash plate type motor/pump. In this paper, kinematic analysis was done on the piston rod mechanism. A series of formula were derived and numerical calculations were done for a set of motor parameters.

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Developing Analysis Model for Evaluation of HCVT Materialization Possibility, and Examining It's Characteristics (HCVT 구현 가능성 평가를 위한 해석모델 개발 및 특성검토)

  • Noh, Daekyung;Jung, Dongsoo;Jang, Joosup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.1
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    • pp.39-46
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    • 2016
  • This paper reviews design validity before manufacturing HCVT prototype through simulation. The component part is being devided, modeled and checked if it works well to an designer's original intent about some active modes. Also, the dynamic characteristic is examined how it changes according to alteration of pressure, friction and leak rate. Finally, HCVT design plan is being confirmed if it could be materialized through those analysis.

Optimization of slope angles of a barge-shaped FPSO from the towing stability and load perspective

  • Kwon, Chang Seop;Yeon, Seong Mo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.786-793
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    • 2021
  • In this study, a parametric investigation is performed using CFD for towing stability and loads according to the forward and aft slope angles of a barge-shaped FPSO. The forward slope angle is considered in a range of 30-60° and the aft slope is examined in a range of 20-50°. As a result of a comparative study based on CFD towing simulations, it is found that the yaw motion is damped out and stabilized when the aft slope is more than 40° regardless of the forward slope angle. The vortex contours in the y-axis plane near the aft slope are analyzed and it is observed that the vortex developed at the bottom knuckle is bent upward along the aft slope when the aft slope is less than 40°, and completely fallen from the bottom knuckle when the aft slope is more than 40°. Based on the results, a guide to forward and aft slope angles of a barge-shaped FPSO is presented from a practical point of view considering towing stability as well as towing load.