• Title/Summary/Keyword: surface table

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A Rational Quantity of Measurement for Finding Flatness of a Surface Table (정반 평면도 평가를 위한 측정점의 합리적인 개수의 결정)

  • Hyun, Chang-Hun;Shin, Sang-Cheol;Park, Hung-Sik
    • Journal of Industrial Technology
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    • v.18
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    • pp.181-186
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    • 1998
  • The flatness is the most important nature for the surface table. For finding such a flatness, the surface is surveyed along a number of straight lines parallel to the edges of table, which form a grid. Next, the variations in height of the grid points are measured relative to a datum point. If the number of such points is increased. It is not necessarily to use many grid points for finding the original flatness of a measured surface table. So, it is necessary to find the rational quantity of such grid points. It is found that about 220 points per $1m^2$ of surface table for measurement is the rational quantity with less than about 15% error of the original flatness.

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Solar Radiation in Korea (한국의 지방별 일사량)

  • Kim, Hyo-Gyeong
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.5 no.3
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    • pp.178-197
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    • 1976
  • Based on the measurement data on Radiation on a Horizontal Surface at 84 different areas in South Korea which were collected and recorded by the Central Meteorological Office, the average values in the period of 5 years from 1971 thru 1975 at 12 particular areas of Gangreung, Gyeongju, Gwangju, Gimhae, Mogpo, Seoul, Iri, Jeju, Jinju, Cheongju and Chungju are indicated in this report. For above 12 areas the following data have been obtained and are indicated in each tables. Annual totalization of Radiation on a Horizontal Surface and its yearly averaged daily totalization$cdots$Table 1. Monthly totalization of Radiation on a Horizontal Surface and its monthly averaged daily totalization$cdots$Table 2 Maximum and minimum values of daily totalization of Radiation on a Horizontal Surface$cdots$Table 3 Daily variation of monthly averaged Radiation on a Horizontal Surface$cdots$Table 4 thru 15 Decade averaged Radiation on a Horizontal Surface$cdots$Table 16 thru 27

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Influence of Operating Condition on Grinding Temperature in High Effect Grinding (고능률 가공에서 연삭 온도에 미치는 연삭 조건의 영향)

  • 김남경;강대민;송지복
    • Journal of the Korean Society of Safety
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    • v.5 no.1
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    • pp.31-39
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    • 1990
  • In this paper, the influence of the table speed, metal removal rate and grinding fluid on long wheel workpiece contact zone at high effect grinding was investigated by theoretical analyses and measuring the temperature, and discussed by the temperature distribution in grinding surface layer. Main results obtained are as follows, 1) Rega.dless of the table speed, the temperature gap of the workpiece(heat influx) is about 6-8 times as high in dry condition as in wet condition. 2) Good grinding condition can be obtained owing to the effect of grinding fluid without any burning defect under the condition of the metal removal rate(1.0mm$^3$/mm.s) in case of wet grinding. 3) When the depth from the surface layer is about 1.25-1.5mm under the condition of the slow table speed, surface temperature goes up higher as the table speed slows down, because long contact time is laked at the surface layer. 4) In case of the same metal removal rate, the lower the table speed becomes, the higher the surface temperature is, because grinding depth has a far more influence on wheel workpiece contact zone than the table speed.

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A Study on the ELID Grinding Properties of Single Crystal Sapphire Wafer using Ultrasonic Table (초음파 테이블을 이용한 단결정 사파이어 웨이퍼의 ELID 연삭가공 특성 연구)

  • Hwang, JinHa;Kwak, Tae-Soo;Lee, Deug-Woo;Jung, Myung-Won;Lee, Sang-Min
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.4
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    • pp.75-80
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    • 2013
  • Single crystal sapphire being used in high technology industry is a brittle material with a high hardness and excellent physical properties. ELID(Electrolytic In-Process Dressing) grinding technology was applied to material removal machining process of single crystal sapphire wafer. Ultrasonic vibration which added to material using ultrasonic table was adopted to efficient ELID grinding of sapphire materials. The evaluation of the ground surface of single crystal sapphire wafer was carried out by means of surface measuring by using AFM(Atomic Force Microscope), surface roughness tester and optical microscope device. As the results of experiment, it was shown that more efficient grinding was conducted when using ultrasonic table. In case of using #170 grinding wheel, surface roughness of ELID ground specimen in using ultrasonic table was superior to ELID ground specimen without ultrasonic table. However, In case of using #2000 grinding wheel, surface roughness of ELID ground specimen in using ultrasonic table was inferior to ELID ground specimen without ultrasonic table.

Effect of Drainage System on ET and Drainage Flows

  • ;Ph.D.,P.E.
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.34 no.E
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    • pp.12-19
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    • 1992
  • The effects of drainage system on evapotranspiration and drainage flows are studied. Data from drainage field experiment at Castalia in North Central Branch, Ohio Agricultural Research and Development Center were used in this study. A water table management model, ADATP (Agricultural Drainage and Pesticide Transport), which was developed by combining the GLEAMS and the subsurface drainage part of the DRAINMOD model with several modifications, was evaluated and used to predict hydrologic components. The ET is very much affected by the presence of tile drainage system but not significantly affected by the surface drainage system. The combined surface and subsurface drainage system gives the largest total outflow values while the surface drainage only system gives the smallest. Comparisons of model predicted and measured values of surface runoff only, subsurface drainage only, and combined surface runoff and subsurface drainage system are in satisfactory agreement. The model predicted values are within the range of the variations of the observed replications in general. Based on the results of the model evaluation study, it is concluded that ADAPT model can be used to design water table management systems.

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Monthly Average Insolation Data on South-Facing Inclined Surfaces (남향경사면의 월평균 전일사량)

  • Kim, Doo-Chun
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.8 no.4
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    • pp.254-259
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    • 1979
  • Radiation data on south-facing surfaces required for the simplified design pro cedures for solar energy systems, have been computed using the method by Liu and Jordan. For the five localities of South Korea selected from reference 6, the factor R for the conversion of the monthly average daily total radiation on a horizontal surface to that on an inclined surface is presented in Table 5. For the other localities, the convession factor R can by computed using Table 2 through Table 4.

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The evaluation for the operation surface mounters using a dynamic network (동적 네트워크를 이용한 표면실장기 운영 평가)

  • 이달상
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.570-573
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    • 1996
  • The evaluation test for the operation of rotary type surface mounters which consist of the reel axis, the index table and the X-Y table, has been performed by comparing the new method with the old one in only fields. Because the problem seeking for the optimal operation of rotary type surface mounters, is NP complete, it is almost impossible to get the optimal solutions of large problems. This paper deals with a dynamic network modeling, which can reduce the effort, the cost, and the time used for the performance test of rotary type surface mounters.

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Effects of 2-dimensional vibration on the surface roughness in micro milling (미세밀링 가공 시 2차원 진동이 표면거칠기에 미치는 영향)

  • Kim, Gi Dae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.4
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    • pp.81-86
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    • 2013
  • For a 2-dimensional(2D) vibration milling, an excitation work-table was developed using two piezoelectric materials orthogonally arranged, where the trochoidal trajectory of a milling tool is combined with 2 dimensional elliptical vibration of a work-table. Applying 3kHz excitation frequency and 7~8mm amplitude of vibration to micro milling process with brass and nickel materials, the roughness in both bottom and side surface is much more improved compared to the surface by conventional milling process, which is attributed to decreased frictional force, increased cutting speed, and rubbing effect of a 2 dimensional vibration.

Intensity of Total Mean Solar Radiation in Korea (한국의 지방별 평균전일사양)

  • Kim Hyo Kyung
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.6 no.3
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    • pp.216-219
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    • 1977
  • Intensity of solar radiation on a horizontal surface at 12 areas in South Korea was indicated in the last report, Vol. 5, No.3 Journal of the S. A. R. E. K. In this report, area of South Korea was devided into 4 zones in latitude, and calculated intensity of total mean solar radiation on horizontal surface, normal surface to sun rays, and vertical surface of south, north, west and east. For the 4 areas, the following data have been obtained and are indicated in each table. Intensity of total mean solar radiation for Seoul, Gimcheon, Jinju and Jeju$\cdots$Table2 thru Table 5.

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Determination of an Optimal Contact Pose for Object Recognition Using a Robot Hand (로봇 손의 물체 인식을 위한 최적 접촉포즈 결정 알고리즘)

  • 김종익;한헌수
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.448-451
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    • 1999
  • In this paper, we propose a new object representation method and matching algorithm for object recognition using a 3-fingered robot hand. Each finger tip can measure normal vector and shapes of a contacting surface. Object is represented by the inter-surface description table where the features of a surface are described in the diagonal and the relations between two surfaces are in the upper diagonal. Based on this table, a fast and the efficient matching algorithm has been proposed. This algorithm can be applied to natural quadric objects.

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