• Title/Summary/Keyword: 3D(three-dimensional)

Search Result 4,304, Processing Time 0.036 seconds

Comparison of Magnetic Field Using Equivalent Reluctance 2D and 3D FEA for Linear Homopolar Synchronous Motor (등가 자기저항 2D와 3D 유한요소해석에 의한 LHSM의 자계 특성 비교)

  • Jang, S.M.;Jeong, S.S.;Yang, H.S.;Ryu, D.W.;Yoon, I.K.;Sung, S.Y.
    • Proceedings of the KIEE Conference
    • /
    • 1999.07a
    • /
    • pp.3-5
    • /
    • 1999
  • The 4-pole LHSM was composed of the figure-of-eight shaped 3-phase armature windings, DC field windings, and the segmented secondary with the transverse bar track. Three dimensional model of LHSM provided the equivalent reluctance and PM model for 2D FEA. From these 2D FEA models, when the motor was fed by DC and 3-phase currents, the magnetic field were calculated and compared with the results of 3D FEA.

  • PDF

A Study on the Construction of a Drone Safety Flight Map and The Flight Path Search Algorithm (드론 안전비행맵 구축 및 비행경로 탐색 알고리즘 연구)

  • Hong, Ki Ho;Won, Jin Hee;Park, Sang Hyun
    • Journal of Korea Multimedia Society
    • /
    • v.24 no.11
    • /
    • pp.1538-1551
    • /
    • 2021
  • The current drone flight plan creation creates a flight path point of two-dimensional coordinates on the map and sets an arbitrary altitude value considering the altitude of the terrain and the possible flight altitude. If the created flight path is a simple terrain such as a mountain or field, or if the user is familiar with the terrain, setting the flight altitude will not be difficult. However, for drone flight in a city where buildings are dense, a safer and more precise flight path generation method is needed. In this study, using high-precision spatial information, we construct a drone safety flight map with a 3D grid map structure and propose a flight path search algorithm based on it. The safety of the flight path is checked through the virtual drone flight simulation extracted by searching for the flight path based on the 3D grid map created by setting weights on the properties of obstacles and terrain such as buildings.

3D Variable Node Solid Elements with Drilling Degrees of Freedom (회전자유도를 가지는 3차원 변절점 고체요소의 개발)

  • 최창근;정근영
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1995.04a
    • /
    • pp.9-16
    • /
    • 1995
  • A new three-dimensional transition solid element with drilling degrees of freedom is presented. The proposed transition element is established by adding variable nodes to a basic 8-node element for an effective connection between the refined region and the coarse. The derivation of the element in this paper is based on the variational principles in which the drilling rotations are introduced as independent variables. This element was also improved through the addition of modified non-conforming modes. Numerical examples show that performance of the element and the applicability to 3D adaptations are satisfactory.

  • PDF

A THREE-DINENSIONAL MEASURING TECHNIQUE APPLIED TO FORGING PRESS MACHINE

  • Xiao, Sun;Shimomoto, Yoichi;Ishimatsu, Takakazu
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1995.10a
    • /
    • pp.138-141
    • /
    • 1995
  • This paper describes a 3-dimensional measuring method for cylindrical huge ingot pressed with forging machine. Target ingot we consider here is rotated around a fixed axis during measurement. Using an image processing technique every profile of cross-section is obtained, and 3D image is reconstructed. One method to calibrate the system setting is also presented. Experimental results reveal that the method are applicable and the algorithm is feasible.

  • PDF

Reference points suitable for evaluation of the additional arch length required for leveling the curve of Spee

  • Cho, Yong-Hwa;Lim, Sung-Hoon;Gang, Sung-Nam
    • The korean journal of orthodontics
    • /
    • v.46 no.6
    • /
    • pp.356-363
    • /
    • 2016
  • Objective: The additional arch length required for leveling (AALL) the curve of Spee (COS) can be estimated by subtracting the two-dimensional (2D) arch circumference, which is the projection of the three-dimensional (3D) arch circumference onto the occlusal plane, from the 3D arch circumference, which represents the arch length after leveling the COS. The purpose of this study was to determine whether the cusp tips or proximal maximum convexities are more appropriate reference points for estimating the AALL. Methods: Sixteen model setups of the mandibular arch with COS depths ranging from 0 mm to 4.7 mm were constructed using digital simulation. Arch circumferences in 2D and 3D were measured from the cusp tips and proximal maximum convexities and used to calculate the AALL. The values obtained using the two reference points were compared with the paired t -test. Results: Although the 3D arch circumference should be constant regardless of the COS depth, it decreased by 3.8 mm in cusp tip measurements and by 0.4 mm in proximal maximum convexity measurements as the COS deepened to 4.7 mm. AALL values calculated using the cusp tips as reference points were significantly smaller than those calculated using the proximal maximum convexities (p = 0.002). Conclusions: The AALL is underestimated when the cusp tips are used as measurement reference points; the AALL can be measured more accurately using the proximal maximum convexities.

3-Dimensional Conformal Radiation Therapy in Carcinoma of The Nasopharynx (비인강암의 3차원 입체조형치료에서 등가선량분포에 관한 연구)

  • Keum Ki Chang;Kim Gwi Eon;Lee Sang Hoon;Chang Sei Kyung;Lim Jihoon;Park Won;Suh Chang Ok
    • Radiation Oncology Journal
    • /
    • v.16 no.4
    • /
    • pp.399-408
    • /
    • 1998
  • Purpose : This study was designed to demonstrate the potential therapeutic advantage of 3-dimensional (3-D) treatment planning over the conventional 2-dimensional (2-D) approach in patients with carcinoma of the nasopharynx. Materials and Methods : The two techniques were compared both qualitatively and quantitatively for the boost portion of the treatment (19.8 Gy of a total 70.2 Gy treatment schedule) in patient with T4. The comparisons between 2-D and 3-D plans were made using dose statistics, dose-volume histogram, tumor control probabilities, and normal tissue complication probabilities. Results : The 3-D treatment planning improved the dose homogeneity in the planning target volume. In addition, it caused the mean dose of the planning target volume to increase by 15.2$\%$ over 2-D planning. The mean dose to normal structures such as the temporal lobe, brain stem, parotid gland, and temporomandibular joint was reduced with the 3-D plan. The probability of tumor control was increased by 6$\%$ with 3-D treatment planning compared to the 2-D planning, while the probability of normal tissue complication was reduced. Conclusion : This study demonstrated the potential advantage of increasing the tumor control by using 3-D planning. but prospective studies are required to define the true clinical benefit.

  • PDF

Evaluation of Coding Performance and Design of Spatial Multiplexer or 3D Endoscopic Image Processing (3D 내시경 영상처리를 위한 다중화기 설계와 부호화 성능평가)

  • Song, C.G.;Lee, S.M.;Lee, Y.M.;Kim, W.K.;Hwang, J.D.;Kim, J.H.;Lee, M.H.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1997 no.11
    • /
    • pp.137-141
    • /
    • 1997
  • In this study, in order to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery, three dimensional endoscopic system is designed. These 3D systems have our features of stereoendoscopic image processing: real time image capture and retrieve; presentation of left and right image on a single monitor; separable processing of the left and right eye images; coding of the 3D endoscopic video. For 3D endoscopic video coding, three approaches are presented based on interlaced picture structure, side-field format structure, and simulcast technique. Experimental results and performances comparisons are presented and analyzed or these approaches. Digital video coding techniques are presented or 3D endoscopic video sequences by means of an MPEG-2 video coding.

  • PDF

A Study on Surface Flattening for 3 Dimensional Shoe Pattern Design (신발패턴의 3차원 설계를 위한 곡면의 평면전개에 관한 연구)

  • Song S. J.;Kim S. H.
    • Korean Journal of Computational Design and Engineering
    • /
    • v.9 no.3
    • /
    • pp.266-275
    • /
    • 2004
  • In this paper, a method for generating the planar developments of three-dimensional shoe upper surfaces is proposed. This method is based on the optimization technique minimizing the geometric error occurred on the developed planar surface. Additionally, a rapid mapping algorithm to transform a curve on flattened plane to original surface (or vice versa) is proposed. These techniques are implemented on the 2D/3D integrated shoe design system. Using this system, a prototype running shoe can be designed more precisely and can be manufactured more quickly.

Effect of pulsed laser heating on 3-D problem of thermoelastic medium with diffusion under Green-Lindsay theory

  • Othman, Mohamed I.A.;Atwa, Sarhan Y.
    • Steel and Composite Structures
    • /
    • v.36 no.3
    • /
    • pp.249-259
    • /
    • 2020
  • In this work, a novel three-dimensional model in the generalized thermoelasticity for a homogeneous an isotropic medium was investigated with diffusion, under the effect of thermal loading due to laser pulse in the context of Green-Lindsay theory was investigated. The normal mode analysis technique is used to solve the resulting non-dimensional equations of the problem. Numerical results for the displacement, the thermal stress, the strain, the temperature, the mass concentration, and the chemical potential distributions are represented graphically to display the effect of the thermal loading due to laser pulse and the relaxation time on the resulting quantities. Comparisons are made within the theory in the presence and absence of laser pulse.

Analysis of 3-Dimensional Hydrodynamic Focusing in Circular Capillary Tube and Rectangular Microchannel (원형 모세관과 사각형 단면의 미세채널에서 3차원 수력학적 집속유동 분석)

  • Yoon, Seong-Hee;Kim, Kyung-Hoon;Kim, Jung-Kyung
    • Journal of the Korean Society of Visualization
    • /
    • v.9 no.2
    • /
    • pp.21-26
    • /
    • 2011
  • Hydrodynamic focusing technique to generate focused flow has been used for flow cytometry in microfluidic devices. However, devices with circular capillary tubes made of glass are not suitable for flow visualization or optical signal detection because the rays of light are distorted at the curved interface. We devised a new acrylic chamber assembled with a pulled micropipette and a rectangular microchannel made of glass. This new channel geometry enabled us to visualize the three-dimensional (3D) flow characteristics with confocal imaging technique. We analyzed the 3D hydrodynamic focusing in a circular capillary tube and a rectangular microchannel over a practical range of flow rates, viscosities and pressure drops.