• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.230-235
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• 2000

In this paper, a surface generation model is presented to simulate surface roughness profile in turning operation. The simulation model takes into account the effect of tool geometry, process parameters, rotational errors of spindle, and the relative vibration between the cutting tool and workpiece. The surface roughness profiles are simulated based on the surface-shaping system. The model has been verified by comparing the experimental values with the simulation values. It is shown that the surface simulation model can properly predict the surface roughness profile.

• 대한산업공학회지
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• 제17권2호
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• pp.1-16
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• 1991

This paper deals with some critical activities of CAPP system such as generation of part description database, part feature recognition, process and operation selection, and sequencing method for turning operation of symmetric rotational parts. The part description database is generated by data conversion module from CAD data, and the part feature is recognized by using both pattern primitives and feature recognition rules. Machining processes and operations are selected based on machining surface features and its sequence is determined by rules acquired from process planning expert. AutoCAD is employed as CAD system and computer program is developed by using Turbo-C on IBM PC/AT compatible system.

• 한국기계가공학회지
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• 제19권10호
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• pp.81-86
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• 2020

A ceramic vacuum chamber feedthrough ceramic insulator is made of Al2O3; the manufacturing process involves filling alumina powder into a urethane mold and pressing it with a rubber press to produce a molded body. Thereafter, manufacturing is completed through primary shape processing, sintering, and secondary shape processing in the green body, which is a pressurized molding body, This work is intended to prevent defects in the first shape processing by improving the ceramic insulator in the green body, and to improve the productivity of the ceramic insulator by determining the optimal processing conditions.

• 한국기계가공학회지
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• 제19권1호
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• pp.100-107
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• 2020

As demand for high value-added products with hard materials increases, the line center is used for producing high value-added products in many industries such as aerospace, automobile fields. The line center is a key device for smart factory automation that can improve the production efficiency and the productivity. Therefore, the development of a mill-turn line center is necessary to produce high value-added products with complex shapes flexibly. In the mill-turn process, a milling process and a turning process are combined. In particular, the turning process needs to increase the rigidity of the spindle. The purpose of this study is to analyze the thermal-structural stability through thermo-structural coupled analysis for a mill-turn spindle with a curvic coupling. The maximum temperature and thermal stability of the spindle were analyzed by thermal distribution. In addition, the thermal deformation and thermal-structural stability of the spindle were analyzed through thermo-structural coupled analysis.

• 한국안전학회지
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• 제9권1호
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• pp.19-27
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• 1994

A laser-based in-process measurement system for the evaluation of surface roughness In turning Is reported. The proposed measuring system makes it possible to detect the surface roughness not only circumferential path but also along the feed direction even during machining. Also, it permits the real-time measurement of surface roughness In dynamic condition.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.15-19
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• 1994

The application of neural network for fault dection of cutting force in turning was introduced. This monitoring system consist of a RBF predicton model and a ART-1 pattern classifier. RBF prediction model predict a cutting force signal. Prediction error of predictor is used for a input vector of ART-1 pattern classifier. Prediction error could be successfully performed to fault signal monitoring of ART-1 pattern classifier.

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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• pp.96-97
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• 2001

A 110 mm diameter aspheric metal secondary mirror for a test model of an earth observation satellite camera was fabricated by ultra-precision single point diamond turning (SPDT) . Without a conventional polishing process, the surface texture of R$\sub$a/=2.8 nm, and the form error of R$\sub$a/=0.05 λ has been stably achieved In a laboratory condition. (omitted)

• 한국기계가공학회지
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• 제11권4호
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• pp.118-124
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• 2012

In this study, we turning mold steel (SKD61) using whisker reinforced ceramic tool (WA1) to get affected factor to surface roughness and regression equation. For this study, we adapt system of experiments. Results are follows; From the analysis of variance, it was found that affected factor to surface roughness was feed rate, cutting speed, depth of cut in order. From multi-regression analysis, we calculated regression equation and the coefficient of determination($R^2$). $R^2$ was 0.978 and It means regression equation is significant. Regression equation means if feed rate increase 0.039mm/rev, surface roughness will increase $0.8391{\mu}m$, if cutting speed increase 50m/min, surface roughness will decrease $0.034{\mu}m$, if depth of cut increase 0.1mm, surface roughness will increase $0.0203{\mu}m$. From the experimental verification, it was confirmed that surface roughness was predictable by system of experiments.

• 한국정밀공학회지
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• 제28권12호
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• pp.1353-1358
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• 2011

LAT(Laser Assisted Turning) is a method that applies a machining process after softening a workpiece in which a preheating process is locally applied to its machining section using laser heat source. LAT shows several advantages, such as high productivity, reduction of manufacturing cost, high quality. Analysis of temperature distribution after preheating for LAT is very difficult due to its very small heat input area and large energy and its movement. Also, the LAT for a square bar is more difficult because the shape of a laser heat source can be changed according to the rotation of the workpiece. In this study, thermal analysis for LAT of square bar was performed using laser heat source projection method. And, the analysis results were compared with the results of the prior study of numerical calculation method. It is thus shown that the proposed method is efficient for the thermal analysis of a shaped bar.

• 한국식품저장유통학회지
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• 제20권2호
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• pp.151-157
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• 2013

본 연구에서는 수확시 숙성 정도가 토마토의 저장 중 품질변화에 미치는 영향을 구명하고자 하였다. 그린하우스에서 재배된 'Rafito' 품종을 각각 turning, pink, red 단계에 수확한 후 $30{\mu}m$ PE 필름으로 포장한 후 $5^{\circ}C$와 $10^{\circ}C$에 두어 1주일 간격으로 경도, 가용성 고형분 함량, 적정산도, 색, 라이코펜 함량, 부패율, 저온장해율을 조사하였다. 저장 3주 이후에 $5^{\circ}C$에서는 저온장해가 $10^{\circ}C$에서는 부패가 높게 발생되었다. $5^{\circ}C$에서는 수확 후 품질변화가 거의 없으므로 완숙과인 red 토마토의 품질 유지에 적합하였나, turning과 pink 토마토는 수확후 숙성과정이 억제되어 저장 2주 후에도 미숙한 상태에 머물렀다. Turning과 pink 토마토를 수확 후 $10^{\circ}C$에 저장하면 수확기에 비해 품질이 향상되었다. 특히, turning 토마토는 $10^{\circ}C$에 2주간 저장할 경우 연화는 억제되어 경도가 높게 유지되면서도, 착색이 완성되고 SSC/TA가 증가하며 라이코펜 함량이 완숙과 수준으로 증가되어 내 외부 품질이 가장 우수하였다. 따라서 red 단계에서 수확된 'Rafito' 토마토의 경우 부패를 억제할 수 있는 $5^{\circ}C$ 저장이 바람직하며, red 단계보다 미숙한 상태에서 수확할 경우 저온에서는 후숙에 의한 품질형성이 억제되므로 $10^{\circ}C$가 적정 온도인 것으로 판단된다.