• Title/Summary/Keyword: Tilting Angle

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Mechanical Properties of 3D Printed Re-entrant Pattern/Neoprene Composite Textile by Pattern Tilting Angle of Pattern (3D 프린팅 Auxetic Re-entrant 패턴의 기울기 각도에 따른 네오프렌 복합 직물의 역학적 특성에 관한 연구)

  • Kim, Hyelim;Kabir, Shahbaj;Lee, Sunhee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.45 no.1
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    • pp.106-122
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    • 2021
  • This study confirmed the mechanical properties of an auxetic re-entrant pattern prepared using 3D printing technology and its composite fabric with neoprene for the production of functional auxetic patterns/textiles for safety shoes. Samples were prepared by the tilt angle of a re-entrant pattern of 0°, 30°, 45°, 60° and 90°, and then analyzed using Poisson's ratio, bending, compression, and tensile properties. A 3D printed auxetic re-entrant pattern (3DP-RE) and its composite fabric (3DP-RE/NP) showed a negative Poisson's ratio in all tilting angles that indicated auxetic properties. The results of the bending property shown that strength of 3DP-RE/NP was 1.5 times lower than NP, but the strain improved 2.0 times. It was confirmed that the deformation of 3DP-RE/NP is possible with a low load. Each sample type of compression behavior indicated similar regardless of the tilting angles; in addition, the compression toughness of 3DP-RE/NP increased 1.2 times compared with NP. In the case of tensile properties, 3DP-RE and 3DP-RE/NP were affected by the tilting angle, samples with 90° (the opposite of load direction) showed best tensile property and toughness. 3DP-RE/NP indicated improved bending, compression, and tensile properties.

Evaluation of Treatment Planning for Head Tilting in WBRT 3D-CRT by TomoDirect mode: a Phantom Study (토모다이렉트를 이용한 3차원 전뇌 방사선치료에서 두상 각도에 따른 치료계획평가: 팬톰 실험)

  • Dae-Gun, Kim;Sang-Hyun, Kim
    • Journal of the Korean Society of Radiology
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    • v.16 no.7
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    • pp.857-862
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    • 2022
  • The purpose of this study was to evaluate a three-dimensional conformal radiotherapy (3D-CRT) treatment plan with regard to head tilting in whole-brain radiotherapy (WBRT) using TomoDirect (TD) mode in Tomotherapy. WBRT 3D-CRT by TD was compared for a total of five head tilt angles (-20°, -10°, 0°. +10° and +20°). The dose homogeneity index (HI) and prescription dose index (CI) were calculated to confirm the target coverage. The maximum and average doses for critical organs such as the lens, eyeball and parotid glands were calculated for different angles of head tilting. The HI and CI were closet to the result value of 1 at the head tilted angle +10° and +20°. At a head tilted angle of +10°, the dose to the lens and eyeballs decreased by about 74% and about 30%, when compared with the reference angle (0°), respectively. The results of this study suggest that a head angle of +10 with chin-up would save adequate target coverage and reduce exposure dose to the lens.

Analysis of Tilting Angle of KOMPSAT-1 EOC Image for Improvement of Geometric Accuracy Using Bundle Adjustment

  • Seo, Doo-Chun;Lee, Dong-Han;Kim, Jong-Ah;Kim, Yong-Seung
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.780-785
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    • 2002
  • As the KOMPSAT-1 satellite can roll tilt up to $\pm$45$^{\circ}$, we have analyzed some EOC images taken at different tilt angles fur this study. The required ground coordinates for bundle adjustment and geometric accuracy, are read from the digital map produced by the National Geography Institution, at a scale of 1:5, 000. These are the steps taken for the tilting angle of KOMPSAT-1 satellite to be present in the evaluation of the accuracy of the geometric of each different stereo image data: Firstly, as the tilting angle is different in each image, the satellite dynamic characteristic must be determined by the sensor modeling. Then the best sensor modeling equation is determined. The result of this research, the difference between the RMSE values of individual stereo images is due more the quality of image and ground coordinates than to the tilt angle. The bundle adjustment using three KOMPSAT-1 stereo pairs, first degree of polynomials for modeling the satellite position were sufficient.

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The Differences of Shoulder Muscle Activity Onset Time according to Body Tilting Angle in Push-up Exercise (Push-up 동작 시 신체기울기에 따른 견관절 주변근의 수축 개시시간 변화)

  • Cho, Yong-Ho;Kim, Sung-Ok;Choi, Jin-Ho
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.2
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    • pp.55-61
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    • 2015
  • PURPOSE: The purpose of this study was to investigate recruiting order and onset time around shoulder muscle during the push-up according to the body tilting angle. METHODS: Twenty healthy young adult subjects were recruited for this study. They had no neurological and musculoskeletal disease. We used the sEMG for recording onset time of shoulder muscles. Shoulder Muscles were anterior deltoid(AD), posterior deltoid(PD), pectoralis major(PM), upper trapezius(UT). Body tilting angle were measured at 0 degree, 30 degree and 60 degree by using tilting table. Muscles contraction onset time were set by the push-up performed 3 times respectively. Mean of 3 measurements were used. And initiate onset time was decided by the Mean ${\pm}2$ SD in the threshold, more than 25ms. RESULTS: There were significant difference at 0 degree, 30 degree and 60 degree(p<.05). Muscles onset time were same order at 0 degree, 30 degree. UT occurred first of all contraction at 0 degree and 30 degree. And then contracted AD, PD, PM. But, at 60 degree, AD was the first contraction, and PM, UT, PD. CONCLUSION: Muscle recruitment order and onset time according to the body tilting was shown the difference when you do push-up. Therefore, this result, shoulder muscle recruitment pattern of according to the body tilting is different and it has to make effective shoulder exercise program.

Development for Tilting Train Dynamics Motion Base

  • Song, Yong-Soo;Shin, Seung-Kwon;Kim, Jung-Seok;Ho, Seong
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1158-1161
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    • 2004
  • This paper describes the construction of a half sphere screen driving tilting simulator that can perform six degree-of-freedom (DOF) motions simulator to a tilting train. The mathematical equations of Tilting Train dynamics are first derived from the 6-DOF bicycle model and incorporated with the bogie, carbody, and suspension subsystems. The equations of motion are then programmed by visual C++ code. To achieve the simulator functions, a motion platform that is constructed by six electric-driven actuators is designed, and its kinetics/inverse kinetics analysis is also conducted. Driver operation signals such as carbady angle, accelerator, and tilting positions are measured to trigger the Tilting dynamics calculation and further actuate the cylinders by the motion platform control program. In addition, a digital PID controller is added to achieve the stable and accurate displacements of the motion platform. The experiments prove that the designed simulator is adequate in performing some special rail road driving situations discussed in this paper.

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Characterization of 3D Printed Wrist Brace with Various Tilting Angles of Re-entrant Pattern Using Thermoplastic Elastomer

  • Ye-Eun Park;Hyejin Lee;Imjoo Jung;Sunhee Lee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.46 no.6
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    • pp.1074-1087
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    • 2022
  • This study reports an optimization of a 3D printed wrist brace (WB) for various tilting angles (0°, 45°, 90°) of the re-entrant (RE) pattern and thickness (2 mm, 4 mm) using thermoplastic polyurethane (TPU) filaments and thermoplastic elastomer (TPE) filaments. The actual printing time, weight, Poisson's ratio, and tensile property of the manufactured samples were analyzed. The results confirmed that the actual printing time and weight increased with increasing thickness, regardless of the filament type. All tilting angles of the WB showed a negative Poisson's ratio (NPR), the largest of which appeared at 90°. The results of the tensile property analysis showed that a 90° tilting angle also had the largest value of elongation and stress. From these results, we conclude that the most suitable wrist brace is one in which the actual printing time is low, the weight is minimized to a thickness of 2 mm, and the tilting angle of the RE pattern is 90° for good shock absorption. The choice of filaments may be decided upon according to the user's preference, since the TPU is stiff and the TPE is elastic.

Study on transient performance of tilting-pad thrust bearings in nuclear pump considering fluid-structure interaction

  • Qiang Li;Bin Li;Xiuwei Li;Quntao Xie;Qinglei Liu;Weiwei Xu
    • Nuclear Engineering and Technology
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    • v.55 no.6
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    • pp.2325-2334
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    • 2023
  • To study the lubrication performance of tilting-pad thrust bearing (TPTBs) during start-up in nuclear pump, a hydrodynamic lubrication model of TPTBs was established based on the computational fluid dynamics (CFD) method and the fluid-structure interaction (FSI) technique. Further, a mesh motion algorithm for the transient calculation of thrust bearings was developed based on the user defined function (UDF). The result demonstrated that minimum film thickness increases first and then decreases with the rotational speed under start-up condition. The influence of pad tilt on minimum film thickness is greater than that of collar movement at low speed, and the establishment of dynamic pressure mainly depends on pad tilt and minimum film thickness increases. As the increase of rotational speed, the influence of pad tilt was abated, where the influence of the moving of the collar dominated gradually, and minimum film thickness decreases. For TPTBs, the circumferential angle of the pad is always greater than the radial angle. When the rotational speed is constant, the change rate of radial angle is greater than that of circumferential angle with the increase of loading forces. This study can provide reference for improving bearing wear resistance.

Design of Low Voltage Piezoelectric Actuated Mirror for Micro-CCR (마이크로 CCR구현을 위한 저전압 구동 압전 반사경 설계)

  • Lee, Duk-Hyun;Yang, Chang-Soo;Park, Jae-Y.
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1454-1455
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    • 2008
  • This paper present a piezoelectric actuated mirror with PZT cantilevers, torsional bars and hinges for Micro-CCR (corner cube retroreflector). The actuated mirror with low voltage and large tilting angle is designed and simulated by using FEM (Finite Element Method) simulator (CoventorWare). The tilting angle of actuated mirror is 2.93$^{\circ}$ at low voltage of 5V.

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Static Walking Algorithm for a Quadruped Robot using Tilting (틸팅을 이용한 4족 보행 로봇의 정적 보행 알고리즘)

  • Lee, Sun-Geol;Jo, Chang-Hyeon;Kim, Byeong-Su
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.8
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    • pp.675-679
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    • 2001
  • This paper presents walking algorithm for a quadruped robot that does not have an upper body. Tilting motion is added to the planned walking trajectory instead of using an extra body segment that is independent on walking trajectory. Area and tracking algorithms are proposed as tilting method and compared with that of off-line tilting and that of no tilting. Computer simulation shows that stability of tilted walking is more improved than that of the usual walking algorithm for general walking paths. It also shows that the tracking method guarantees stability and best mobility.

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Experimental Study on the Characteristics of Misaligned Self-equalizing Tilting Pad Thrust Bearing (자려 평형 틸팅 패드 스러스트 베어링의 정렬불량에 따른 베어링 특성에 관한 실험적 연구)

  • Song, AeHee;Jo, HyunJun;Choi, SeongPil;Kim, SeonJin
    • Tribology and Lubricants
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    • v.36 no.1
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    • pp.27-33
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    • 2020
  • Self-equalizing tilting pad thrust bearings are usually employed in turbomachines to achieve high stability and reliability. A tilting pad bearing can incorporate self-equalizing links to handle the misalignment between the bearing and the thrust collar. In this popular design method, the pads sit on the upper-level plates and the lower-level plates stay on the retainer base. With misalignment, the pads that are heavily loaded are pushed down. Consequently, the link pushes up the pads on the opposite side, keeping the bearing surface parallel to the thrust collar surface. The self-equalizing link is used to handle the misalignment from the thermal and mechanical effects. In this study, the experimental investigation deals with the performance of self-equalizing tilting pad thrust bearings. The test rig for evaluating the performance of bearing is developed which can control the misalignment angle. Simultaneous measurements are taken for the force acting on each pad. Pad metal temperature and oil film thickness are functions of the shaft speed, bearing load, misalignment angle, and design of leveling plates. The effect of misalignment on bearing performance is discussed. The results demonstrate that the load on each pad depends on the test conditions(especially misalignment angle), and the load influences the performance of bearings.