• Title/Summary/Keyword: planes

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Calculation of the coupled free, transverse vibrations of the multi-supported shaft system by transfer matrix method (전달매트릭스법에 의한 다점지지축계의 연성자유횡진동계산에 관한 연구)

  • 안시영;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • v.7 no.1
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    • pp.49-63
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    • 1983
  • Coupled transverse shaft vibrations have become the target of great concern in high powered ships such as container ships. Due to increasing ship's dimensions and high propulsive power, resonance frequencies of the propeller shaft system tend to decrease and can appear in some cases within the operating speed range of engine. In this connection, the coupled free transverse vibrations of shaft system in two planes are theoretically investigated. This shaft system carries a number of discs and is flexibly supported by a number of bearing stiffness are considered for the calculation. Transfer matrix method is applied to calculate the shaft responses in both planes. A digital computer program is developed to calculate the shaft responses of the coupled transverse vibrations in two planes. An experimental model shaft system is made. It is composed of a disc, shafts, ball bearings thrust bearings and flexible bearing supports. The shaft system is excited by an electrical magnet, and shaft vibration responses in two planes are measured with the strain gage system. From these measurements, the natural frequencies of the shaft system in both planes are found out. The developed program is also used to calculate the shaft vibration responses of experimental model shaft system. From the results of these calculations, the natural frequencies of shaft system in two planes are derived. Theoretical predictions of model shaft natural frequencies show good agreements with its esperimental measurements.

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Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation

  • Yoon, Kaeng Won;Yoon, Suk-Ja;Kang, Byung-Cheol;Kim, Young-Hee;Kook, Min Suk;Lee, Jae-Seo;Palomo, Juan Martin
    • Imaging Science in Dentistry
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    • v.44 no.3
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    • pp.207-212
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    • 2014
  • Purpose: This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Materials and Methods: Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. Results: The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. Conclusion: In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

Orientation Dependent Directed Etching of Aluminum

  • Lee, Dong Nyung;Seo, Jong Hyun
    • Corrosion Science and Technology
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    • v.8 no.3
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    • pp.93-102
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    • 2009
  • The direct-current electroetching of high purity aluminum in hot aqueous-chloride solution produces a high density of micrometer-wide tunnels whose walls are made up of the {100} planes and penetrate aluminum in the <100> directions at rates of micrometer per second. In the process of the alternating-current pitting of aluminum, cathodic polarization plays an important role in the nucleation and growth of the pits during the subsequent polarization. The direct-current tunnel etching and alternating-current etching of aluminum are basically related to the formation of poorly crystallized or amorphous passive films. If the passive film forms on the wall, a natural misfit exists between the film and the aluminum substrate, which in turn gives rise to stress in both the film and the substrate. Even though the amorphous films do not have directed properties, their stresses are influenced by the substrate orientation. The films on elastically soft substrate are likely to be less stressed and more stable than those on elastically hard substrate. The hardest and softest planes of aluminum are the {111} and {100} planes, respectively. Therefore, the films on the {111} substrates are most likely to be attacked, and those on the {100} substrates are least likely to be attacked. For the tunnel etching, it follows that the tunnel walls tend to consist of the {100} planes. Meanwhile, the tunnel tip, where active corrosion takes place, tend to be made of four closely packed {111} planes in order to minimize the surface energy, which gives rise to the <100> tunnel etching.

A Study on Theo van Doesburg's Plastic Experiments with Colored Planes (반 두즈버르그의 색면 조형 실험에 관한 연구)

  • Park, Young-Kyung
    • Korean Institute of Interior Design Journal
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    • v.16 no.3 s.62
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    • pp.30-37
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    • 2007
  • This research is to find out the characteristics and significance of the plastic experiments with colored planes in Theo van Doesburg's works. Based on the analysis, the following results have been obtained. First, Thea van Doesburg's plastic experiments with colored planes started from the paintings in 1916-1918. series and series were made of the ion of still life or human motion. These paintings were intended to make effects of rhythm, acceleration and simultaneity. Second, he colored the outer and inner architectural surface with primary colors. The expression of visual. rhythm on the color design for De Vonk, Districts Housing Projects VIII & IX in Spangen, Multi-Housing in Oosterstraat, Friesian Housing, Landbouw Winter School, and University Hall in Amsterdam embodied the concept of painting-in-architecture. Third, the field of these experiments were extended into the architectural space. As a results, $H\hat{o}tel$ Particulier and Maison d'Artiste was shown on the Architectural Exhibition in Paris in 1923. The colored planes were used as a construction material. They generated the dynamic space in architecture. Fourth, through the pictorial works like Architectural Analysis, Contra-Composition, Simultaneous Composition or Simultaneous Contra-Composition, Tesseract and Aubette Cinema-Dancing Hall, he created the concepts of simultaneous integration including nature and the environments as well as space-time in the architecture.

Coupling Performance Analysis of a Buried Meshed-Ground in a Multi-layered Structure

  • Joung, Myoung-Sub;Park, Jun-Seok;Kim, Hyeong-Seok;Lim, Jae-Bong;Cho, Hong-Goo
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.6
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    • pp.282-287
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    • 2004
  • Since the manufacturing process in the LTCC process does not allow solid ground planes between ceramic layers to isolate the signal lines, the buried ground should be realized as a meshed ground plane. Both characteristic impedances of the signal lines and couplings between different signal layers are influenced by the properties of these meshed planes. In this paper, we propose a new analysis method for coupling behavior between internal transmission lines, which are isolated by the buried meshed-ground planes. The coupling behavior between layers isolated by meshed-ground planes is investigated by the coupled-transmission line model for the isolated layers. The coupling factors between isolated lines with the meshed-ground are extracted by 2-D FEM calculations.

Analysis for Pure Translation and Couple Modes of an Elastically Suspended Rigid Body with Planes of Symmetry (대칭면을 갖는 단일 강체의 순수 병진 및 순 짝힘 모우드 해석)

  • 김동욱;최용제
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.260-267
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    • 2002
  • For an elastically suspended rigid body with the planes of symmetry in a three dimensional space, a novel analysis fur the vibration modes is presented. From the decompositions of the stiffness and inertia matrices, the conditions for the existence of pure translation and pure couple modes are analyzed for an elastically suspended rigid body with the planes of symmetry. From this analysis, it can be showed that how the structure of stiffness and inertia must be related in order to produce the pure translation and pure couple modes when an elastically suspended rigid body has one, two, or three planes of symmetry.

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Anisotropic Etching of Silicon in Aqueous TMAH/IPA Solutions (수용성 TMAH/IPA 용액의 실리콘 이방성 식각)

  • 박진성;송승환;정귀상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.334-337
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    • 1996
  • Si anisotropic etching is a key technology for micromachining. The main advantages of tetramethyl ammonium hydroxide (TMAH)-based solution are their full compatibility with IC process. In this work the anisotropic etching of single crystal Si in a TMAH (($CH_3$)$_4$NOH) based solution was studied. The influence of the addition of IPA to TMAH solution on their etching characteristics was also presented. The crystal planes bounding the etch front and their etch rates were determined as a function of temperature, crystal orientation, and etchant concentration. The etch rates of (100) oriented Si crystal planes decreased linearly with increasing the IPA concentration, The etched (100) planes were covered by Pyramidal-shaped hillocks below 15 wt.%, but very smooth surfaces were obtained above 20 wt.%. The addition of IPA to TMAH solution leads to smoother surfaces of sidewalls etched planes.

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The Field of Power/Ground Planes influenced by the HPEM Source, and its Damage Reduction

  • Kahng, Sung-Tek;Kim, Hyeong-Seok
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.406-410
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    • 2012
  • This paper looks into the field inside the wide rectangular box structure that is excited by the High Power Electromagnetic(HPEM) source as a potential threat to electric grid and communication networks causing malfunction or destruction. The rectangular box is assumed power/ground planes and its internal field is calculated by the cavity model with the lightning strike excitation as an HPEM pulse. The accuracy of the calculation method employed here is validated through a $156mm{\times}106mm{\times}508{\mu}m$ parallel metallic plate case which is manufactured and tested, and is applied to the size of a building. With the help of the cavity model that takes into account loading, the level of the electric field is shown to decrease when a metal pillar is loaded between the power and ground planes.

Three Dimensional Medical Image Rendering Using Laplace's Equation (라플라스 방정식의 해를 이용한 삼차원 의학 영상 랜더링)

  • Kim, S.M.;Ahn, C.B.
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2918-2920
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    • 2000
  • A new multi-planar interpolation technique for three dimensional medical image rendering is proposed. In medical imaging. resolution in the slice direction is usually much lower than those in the transverse planes. The proposed method is based on the solution of the Laplace's equation used in the electrostatics. In this approach. two contours in the source and destination planes for a given object is assumed to have equi-potentials. Some preprocessing and post-processing including scaling. displacement. rotation from the centers of mass are involved in the algorithm. The interpolation solution assumes mostly smoothing changes in between the source and destination planes. Simultaneous multiple interpolation planes are inherently obtained in the proposed method. Some experimental and simulation results are shown.

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BOOLEAN GEOMETRY (3)

  • Kim, Chang-Bum
    • Journal of applied mathematics & informatics
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    • v.5 no.2
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    • pp.349-356
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    • 1998
  • We give the new formulas counting the total number of all lines planes and tetrahedrons in the n-dimensional Boolean space.