• Title/Summary/Keyword: Surface arrangement

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Implementation of a Surface Generating System Employing Wires (철선을 이용한 표면 제시 시스템의 구현)

  • 김희국;김도형;김해수;김민건;강대임;박연규
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.6
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    • pp.514-521
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    • 2000
  • In this study, a surface generating system with a bundle of wires, which can reproduce a certain range of surface roughness of the objects without direct machining process, is implemented. The system consists of a bundle of wires, a PZT actuator, a vertical table system actuated linearly along two perpendicular axes, and an image processing system. Through the development of the operational software for all of those subsystems by a common language(Visual C++) of the implemented system, the complete process except arrangement of a bundle of wires are automated. Lastly, through the experiments of generating the flat surface of some virtual object and then of measuring the reproduced surface roughness, it is confirmed that the implemented system has excellent performance.

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Three-dimensional analysis of the arrangement of microtubules of the outer segment in the ciliary-type photoreceptor cell in the Onchidium dorsal eye

  • Katagiri, Nobuko;Shimatani, Yuichi;Katagiri, Yasuo
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.284-286
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    • 2002
  • The inverted retina of the Onchidium dorsal eye (DE) is composed only of ciliary-type photoreceptor cells (CC's). The outer segment (OS) of the CC is a concentric lamellar structure consisting of many modified ciliary membranes and stains positively with anti-$\beta$-tubulin antibody. Near the base of the OS there are about 30 basal bodies each connecting individually to a cilium. The cilia are rod-shaped at the base, progressing upwards to a flattened sheet-like shape with increasing surface area. Three-dimensional analysis on serial sections demonstrates the ladle-shape of a modified cilium. Many modified cilia wrap around each other like the leaves of a cabbage. Nine pairs of microtubules (MT's) are located regularly in a ring at the base of the cilium, gradually losing their regular arrangement towards the periphery, where they separate into two subgroups that are contained within two swollen portions of a modified cilium. Within the CC of the Onchidium DE, MT's in the modified cilium exist as two poles extending longitudinally in a thin expanded ciliary membrane. This arrangement may support the photoreceptive OS and serve to maintain its structural integrity.

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조선 도장 공장 운영 방안 수립에 관한 연구

  • 최동희;박주철
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2001.10a
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    • pp.286-289
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    • 2001
  • This paper deals with the procedures of effective mid-term Operation Planning establishment for painting shop in shipbuilding. and develop prototype system. In general, the block painting process consists of two stages such as blasting operation for surface preparation and painting operation for paint application for blocks. Weather condition is a potent Influence on those operations. The procedures consists of four steps, Load analysis, Generate alternative simulation plan. Implementation of Allocation automation module and Compare result of each simulation plan. Explain of each step. as follows, 1.step, Load analysis measure amount of assigned workload and manhour. 2.step, simulation scheme include alterable control variable such as overtime, weather. Auto allocating module carry out feasibility of simulation plan. 3.step, Allocation automation module are composed of three algorithms, as followings: - the block allocation algorithm that determines the number of blocks to be processed each day, - the team allocation algorithm that allocates blocks to worker groups. - the block arrangement algorithm that arrange blocks in blasting and painting cells. Since the block arrangement algorithm is conducted simultaneously with the team allocation algorithm, the total structure of the operating algorithms is considered to have two phases: first, daily load balancing with capacity limit and second, team allocation considering arrangement each day 4 step, Comparing result of each simulation plan. and select best simulation plan.

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STOKES FLOW THROUGH A MICROCHANNEL WITH PROTUBERANCES OF STAGGERED ARRANGEMENT (엇갈린 배열의 돌출물들이 존재하는 마이크로채널 내의 스톡스 유동)

  • Son, Jeong Su;Jeong, Jae-Tack
    • Journal of computational fluids engineering
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    • v.20 no.4
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    • pp.109-115
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    • 2015
  • In this study, the Stokes flow in the microchannel is analysed where the semicircular protuberances with constant spacing are attached on the upper and lower walls with staggered arrangement. For the low Reynolds number flow in microchannel, Stokes approximation is used and the periodicity and symmetry of the flow are considered to determine the stream function and pressure distribution in the flow field by using the method of least squared error. As results, the streamline patterns and pressure distributions in the flow field are shown for some specific values of the size and spacing of the protuberances, and shear stress distributions on the surface of semicircular protuberances are plotted. Especially, for an important physical property, the average pressure gradient along the microchannel is obtained and compared with that for the case of in-phase arrangement of the upper and lower protuberances. And, for the small clearance between the protuberances of upper and lower walls or between the protuberances and the opposite wall, the average pressure gradient is derived from the lubrication theory and compared with that of the present study.

Multiobjective Optimal Double-Layer PM Rotor Structure Design of IPMSM by Response Surface Method and Finite Element Method (반응표면법을 이용한 매입형 영구자석 동기전동기의 이층 영구자석 회전자 구조 다목적 최적 설계)

  • Choi, Gil-Sun;Hahn, Sung-Chin
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.6
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    • pp.123-130
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    • 2010
  • In general, a design method based on the equivalent magnetic circuit has been used for basic design of Interior Permanent Magnet Synchronous Motor(IPMSM). However, the equivalent magnetic circuit method has difficulty in considering the arrangement of PM. IPMSM has high degree of freedom for PM rotor design. In this paper, we proposed the multiobjective optimal design method considering the arrangement of PM for the double-layer PM rotor structure that minimizes the torque ripple as well as maximizes the torque of IPMSM. The design variables of double-layer PM rotor structure are obtained from the Response Surface Method. Torque and torque ripple were calculated by Finite Element Method.

Experimental study and numerical modeling of liquid sloshing damping in a cylindrical container with annular and sectorial baffles

  • Mohammadi, Mohammad Mahdi;Moosazadeh, Hamid
    • Advances in aircraft and spacecraft science
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    • v.9 no.4
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    • pp.349-366
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    • 2022
  • The ability of baffles in increasing the sloshing damping is investigated in this study by theoretical, numerical, and experimental methods. Baffles Installed as separators in containers, can change the dynamic properties of sloshing. The main purpose of this study is to investigate the effect of baffle placement.The main purpose of this study is to investigate the effect of placing baffles in order to provide appropriate frequencies and damping and to present a practical baffle arrangement in the design ofsloshing. In this regard, an experimental setup is designed to study the fluid sloshing behavior and damping properties in cylindrical tanks filled up to an arbitrary depth. A new combination of annular and sectorial baffles is employed to evaluate fluid sloshing in the tank. The results show that the proposed baffle arrangement has a desired effect on the damping and fluid sloshing frequencies and optimally satisfies the anticipated design requirements. In addition, the theoretical frequencies exceed empirical frequencies at the points far from baffles, while at the points close to baffles, the empirical ones are higher than theoretical ones. Also, at the depths near the bottom of container sloshing frequencies are not affected by sectorial baffles, although the theoretical curve predicts a reduction in the fundamental frequency of sloshing. Finally, the results of finite volume and finite element methods which compared with experimental data, indicated a good agreement between different approaches.

A Graphical Method for Evaluating the Effect of Blocking in Response surface Designs Using Cuboidal Regions

  • Sang-Hyun Park;Dae-Heung Jang
    • Communications for Statistical Applications and Methods
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    • v.5 no.3
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    • pp.607-621
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    • 1998
  • When fitting a response surface model, the least squares estimates of the model's parameters and the prediction variance will generally depend on how the response surface design is blocked. That is, the choice of a blocking arrangement for a response surface design can have a considerable effect on estimating the mean response and on the size of the prediction variance even if the experimental runs are the same. Therefore, care should be exercised in the selection of blocks. In this paper, we prognose a graphical method for evaluating the effect of blocking in a response surface designs using cuboidal regions in the presence of a fixed block effect. This graphical method can be used to investigate how the blocking has influence on the prediction variance throughout the entire experimental region of interest when this region is cuboidal, and compare the block effect in the cases of the orthogonal and non-orthogonalblockdesigns, resfectively.

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Coil Spring Inspection for Reliability Assurance of Automobile Suspension System using Guided Wave

  • Nohyu kim;Park, Woon-Yong
    • International Journal of Reliability and Applications
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    • v.5 no.1
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    • pp.37-46
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    • 2004
  • Coil spring of automobile suspension system is very important to safety and dynamics of passenger car and requires a highly advanced quality control during manufacturing processes. Surface cracks on the coil spring rod produced by mechanical machining and heat treatment may cause a severe accident and large cost to the manufacturer. In order to detect surface cracks of the rod, guided wave technique is applied for a fast total volumetric inspection. Pochhammer equation is studied to investigate the dispersion characteristics of the guided wave in the spring rod and optimal wave modes sensitive to the surface crack are selected experimentally to design the experimental arrangement for the generation of guided wave. Rod samples with different size of artificial axial EDM notch on the surface ranging from 50${\mu}{\textrm}{m}$ to 1 mm are examined by guided wave and inspection results discussed.

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Investigation into the variation on Si wafer by RTA annealing in $H_2$ gas (RTA를 이용하여 수소 열처리한 실리콘 웨이퍼의 표면 및 근처의 변화 연구)

  • 정수천;이보영;유학도
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.1
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    • pp.42-47
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    • 2000
  • The surface structure and the crystalline features in the near surface region have been investigated for CZ(Czochralski) grown Si wafers. Si wafers were annealed by RTA (Rapid Thermal Annealing) method in H$_2$ambient after mirror polished process. The densities of COPs (Crystal Originated Particles) after RTA process were remarkably decreased at the surface and in the region of 5um depth from the surface as well. terrace type surface structure which was formed by etching and re-arrangement of Si atoms during $H_2$annealing process also has been observed.

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Effects of Rotation Speed on Heat Transfer and Flow in a Coolant Passage with Turning Region (II) - Parallel Ribbed Duct - (곡관부를 가지는 내부 냉각유로에서 회전수 변화에 따른 열전달 및 유동 특성 (II) - 평행한 요철배열 덕트 -)

  • Kim Kyung Min;Kim Yun Young;Lee Dong Hyun;Cho Hyung Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.8 s.239
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    • pp.911-920
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    • 2005
  • The present study investigates heat/mass transfer and flow characteristics in a ribbed rotating passage with turning region. The duct has an aspect ratio (W/H) of 0.5 and a hydraulic diameter ($D_h$) of 26.67 mm. Rib turbulators are attached in the parallel arrangement on the leading and trailing surfaces of the passage. The ribs have a rectangular cross section of 2 m (e) $\times$ 3 m (w) and an attack angle of $70^{\circ}$. The pitch-to-rib height ratio (p/e) is 7.5, and the rib height-to-hydraulic diameter ratio (e/$D_h$) is 0.075. The rotation number ranges from 0.0 to 0.20 while the Reynolds number is constant at 10,000. To verify the heat/mass transfer augmentation, internal flow structures are calculated for the same conditions using a commercial code FLUENT 6.1. The results show that a pair of vortex cells are generated due to the symmetric geometry of the rib arrangement, and heat/mass transfer is augmented up to $Sh/Sh_0=2.9$ averagely, which is higher than that of the cross-ribbed case presented in the previous study for the stationary case. With the passage rotation, the main flow in the first-pass deflects toward the trailing surface and the heat transfer is enhanced on the trailing surface. In the second-pass, the flow enlarges the vortex cell close to the leading surface, and the small vortex cell on the trailing surface side contracts to disappear as the passage rotates faster. At the highest rotation number ($R_O=0.20$), the turn-induced single vortex cell becomes identical regardless of the rib configuration so that similar local heat/mass transfer distributions are observed in the fuming region for the cross- and parallel-ribbed case.