• Title/Summary/Keyword: Large surface

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Improvement of the Stereo Vision-Based Surface-Strain Measurement System for Large Stamped Parts (중.대형 판재성형 제품의 곡면변형률 측정을 위한 스테레오 비전 시스템의 개선)

  • 김형종;김두수;김헌영
    • Transactions of Materials Processing
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    • v.9 no.4
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    • pp.404-412
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    • 2000
  • It is desirable to use the square grid analysis with the aid of the stereo vision and image processing techniques in order to automatically measure the surface-strain distribution over a stamped part. But this method has some inherent problems such as the difficulty in enhancement of bad images, the measurement error due to the digital image resolution and the limit of the area that can be measured at a time. Therefore, it is still hard to measure the strain distribution over the entire surface of a medium-or large-sized stamped part even by using an automated strain measurement system. In this study, several methods which enable to solve these problems considerably without losing accuracy and precision In measurement are suggested. The superposition of images that have different high-lightened or damaged part from each other gives much enhanced image. A new algorithm for constructing of the element connectivity from the line-thinned image helps recognize up to 1,000 elements. And the geometry assembling algorithm including the global error minimization makes it possible to measure a large specimen with reliability and efficiency.

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AAO Template Morphology Controlled by Variation of Anodizing Condition (양극 산화 조건 변화에 따른 AAO Template Morphology 제어)

  • Jo, Ye-Won;Lee, Sung-Gap;Kim, Kyeong-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.4
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    • pp.249-251
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    • 2015
  • In this study, the application of biosensor having a large surface area for more effective and AAO (anomic aluminium oxide) template in order to gain concentration and voltage of anodizing process morphology changes to the control of experiments were conducted. The biosensor surface may increase the response characteristics by having a large surface area. So the entrance to a little more efficient wide depth sensing experiment was carried out to obtain a structure body with a branch shape with a large surface area with increasing. Experimental results from the FE-SEM observation was obtained template morphology. As a result, depending on the anodizing time, the depth of the layer of aluminum oxide was found that it was confirmed that the deepening of the pore size changes according to anodizing condition. And measuring the detection performance according to the conditions in the electrolyte and the reaction because of blood using a biosensor measuring sensing property according to the depth of the pore depth is considered that does not have a significant impact.

Unit Loads of Pollutants in a Paddy Fields Area with Large-Scaled Plots during Irrigation Seasons (관개기 대구획 광역논에서의 오염부하 원단위)

  • 오승영;김진수;김규성;김선종;윤춘경
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.2
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    • pp.136-147
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    • 2002
  • Characteristics of unit loads of pollutants were investigated at a paddy fields area(Soro-ri) with large-scaled plots on loam soil during irrigation seasons of 1999 ∼2000. The average irrigation requirement of experimental paddy area are estimated at over 3,000 mm. The unit loads of pollutants in paddy fields area are determined by subtracting irrigation water load from outflow load (percolated and surface outflow loads). Surface outflow load in rainy days was calculated using the relationships of discharge and load, which are grouped into fertilizing and non-fertilizing periods. The ratios of the surface outflow load in rainy days to the total surface outflow load are 16.4% for T-N, 26.8% for T-P, and 23.3% far CODc,. The unit loads of pollutants show month-to-month and year-to-year variations, and monthly unit load of pollutants can show negative values, indicating that the paddy area acts as the pollutants sink. The average unit loads of the pollutants during irrigation seasons were estimated at 18.2 kg/ha fur T-N, 0.31 kg/ha for T-P, and 43.3 kg/ha for CODc,, which are smaller than the reported values for Kosei area in Japan.

A Study on the Approximation Method of the Hydrodynamic Forces on the VLFS (초대형 부유식 해양구조물에 작용하는 유체력 추정에 관한 근사계산법의 연구)

  • 박노식
    • Journal of Ocean Engineering and Technology
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    • v.11 no.1
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    • pp.74-83
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    • 1997
  • This study is to develop a practical calculation method of hydrodynamic force and motion response on very large floating structures of multiple legs. To investigate the effecr of hydrodynamic interfaction and of free surface on the reaponses of very large floating structures in regular waves, four kind of models are considered, ie. 1, 4, 64, 21248 column with footing. Based upon the results of this study, it is found that the middle parts of very large floating structures have small diffration effects. Therefore only out side parts are used to determine the hydrodynamic forcea for taking into account the effects of interaction.

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Assessment of Insulation Condition in Operating Large Turbine Generator (운전중인 대형 터빈발전기에서 절연상태 평가)

  • 김희동
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.6
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    • pp.324-329
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    • 2004
  • Six stator slot couplers(SSC) and a flux probe sensor installed on the stator winding slots of large turbine generator. Assessment of insulation condition has been based upon the measurements of partial discharge(PD) of stator windings and shorted-turn of rotor windings in operating large turbine generator. The maximum PD magnitude(Qm), normalized quantify number(NQN), PD pattern and shorted-turn were measured using on-line insulation condition monitoring system. The NQN and Qm of slot PD side in the phase A are indicated the highest value in six SSC sensors. Monitoring system results showed that discharge at conductor surface and internal discharge were detected at the surface of stator winding and in voids of the groundwall insulation. Insulation of stator and rotor windings in large turbine generator was judged to be in good condition.

Element Technology of the Ultra-Precision Machine Tools for Machining the Large Surface Micro Features (대면적 미세형상 복합 가공기의 요소기술)

  • Song C.K.;Park C.H.;Hwang J.H.;Kim B.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.86-93
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    • 2005
  • In this paper, we discuss the merits of mechanical machining to generate micro features on large surfaces. An overseas technology trend related to the micro machining and dedicated machinery is also presented. We provide an overview of what characteristics the machinery is required to have to generate micro features on large surfaces and what kind of technical barriers need to be overcome to put the technology to practical use.

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Guidelines of 2D Pattern Development Process for 3D Fitted Cover of Character Toys (캐릭터 인형용 밀착커버 패턴개발 프로세스의 가이드라인)

  • Lee, Heeran
    • Fashion & Textile Research Journal
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    • v.19 no.5
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    • pp.635-645
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    • 2017
  • The industry of character toys is increasing and new characters are constantly being developed. However, the development of 2D cover patterns for toys is time-consuming due to frequent pattern modifications made through trial and error. Studies are now underway to obtain 2D clothing patterns from 3D body data, however, little research has been done on 2D pattern of character toys. This study suggests efficient guidelines to develop 2D cover patterns with a reasonable accuracy and processing time. Two 3D models of a dog and rabbit were used to develop 2D cover patterns. Independent variables of this study are set as 3 levels of triangle area (small, medium, and large) that influence the efficacy of 3D and 2D pattern development. The determination of the appropriate triangular area was based on the area and shape change of the 2D pattern. A medium or large triangle area was shown to be suitable for a character dog with a smooth curved surface. However, the appropriate triangle area was small if the characteristics of the curved surface are complicated as in the case of rabbit. The head of a dog (a double-curved surface) and the curved forepaw of a rabbit (a triangular area) should be small when the characteristics of the curved surface (such as the hind leg of a rabbit having a large convex surface and a small surface area) are complicated. Grouping by 3D surface characteristics could be a suitable guideline for the triangle area selection.

ANALYSIS OF THIN FILM POLYSILICON ON GLASS SYNTHESIZED BY MAGNETRON SPUTTERING

  • Min J. Jung;Yun M. Chung;Lee, Yong J.;Jeon G. Han
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2001.11a
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    • pp.68-68
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    • 2001
  • Thin films of polycrystalline silicon (poly-Si) is a promising material for use in large-area electronic devices. Especially, the poly-Si can be used in high resolution and integrated active-matrix liquid-crystal displays (AMLCDs) and active matrix organic light-emitting diodes (AMOLEDs) because of its high mobility compared to hydrogenated _amorphous silicon (a-Si:H). A number of techniques have been proposed during the past several years to achieve poly-Si on large-area glass substrate. However, the conventional method for fabrication of poly-Si could not apply for glass instead of wafer or quartz substrate. Because the conventional method, low pressure chemical vapor deposition (LPCVD) has a high deposition temperature ($600^{\circ}C-1000^{\circ}C$) and solid phase crystallization (SPC) has a high annealing temperature ($600^{\circ}C-700^{\circ}C$). And also these are required time-consuming processes, which are too long to prevent the thermal damage of corning glass such as bending and fracture. The deposition of silicon thin films on low-cost foreign substrates has recently become a major objective in the search for processes having energy consumption and reaching a better cost evaluation. Hence, combining inexpensive deposition techniques with the growth of crystalline silicon seems to be a straightforward way of ensuring reduced production costs of large-area electronic devices. We have deposited crystalline poly-Si thin films on soda -lime glass and SiOz glass substrate as deposited by PVD at low substrate temperature using high power, magnetron sputtering method. The epitaxial orientation, microstructual characteristics and surface properties of the films were analyzed by TEM, XRD, and AFM. For the electrical characterization of these films, its properties were obtained from the Hall effect measurement by the Van der Pauw measurement.

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Structural Features of Glandular and Non-glandular Trichomes in Three Species of Mentha

  • Choi, Jang-Sean;Kim, Eun-Soo
    • Applied Microscopy
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    • v.43 no.2
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    • pp.47-53
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    • 2013
  • The trichomes on leaves of three species of Mentha such as M. spicata, M. suaveolens, and M. piperita var were examined by scanning electron microscopy. Simple non-glandular trichomes and peltate glandular trichomes were distinctively occurred on these leaves. In M. spicata, short and sharp non-glandular trichomes were dominantly appeared on adaxial surface, whereas capitate glandular trichomes were commonly localized on abaxial surface. In M. suaveolens, non-glandular trichomes were identified with simple unbranched and branched. Unbranched trichomes which were sharp and pointed in shape occurred on adaxial surface, however, branched and v-shaped trichomes appeared abundantly on abaxial surface. Peltate trichomes consisted of a large eight-celled head. Small capitates trichomes consisted of a cylindrical head with an one-celled uniseriate stalk. In M. piperita var, single non-glandular trichomes and peltate trichomes were present on adaxial surface. Small capitate trichomes consisted of a globose unicellular head with a two- or three-celled uniseriate stalk. Peltate trichomes were distinctly present on abaxial surface, whereas they were not observed on adaxial surface. The trichomes were less dense in this species. Peltate trichomes consisted of a large eight-celled head, with an enlarged secretory cavity, attached to an one-celled short stalk.

Optimization of Polishing Conditions for Anodized Inner Surfaces in Large Hydraulic Devices (아노다이징 처리된 대형 유압장치의 내면에 대한 연마 조건의 최적화)

  • Choi, Su-Hyun;Cho, Young-Tae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.7
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    • pp.14-21
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    • 2019
  • Large-diameter hydraulic devices such as the hydraulic reservoir in aircraft that serves to balance the hydraulic pressure in the various hydraulic devices in the cabin and to store hydraulic oil are operated by the internal piston systems. However, since this operates in an environment with high temperature and humidity, it may cause the inner surface to flake during its operation. Therefore, an anodizing surface treatment is applied to improve the corrosion resistance, abrasion resistance, and smooth operation. However, anodizing increases the surface roughness. Accordingly, the polishing process that improves the surface roughness after anodizing is important. However, the existing polishing process is performed manually, which results in an inefficient process. Therefore, in this study, we selected the optimum polishing conditions for effective polishing using the experimental design to improve the polishing process for the $Al_2O_3$ film that forms after anodization. Through experiments, we confirmed that the surface uniformity after polishing was superior as the feed rate was slower when the same polishing time had been applied.