• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.141-142
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• 2006

This paper describes estimation method for 2D position error of planar XY stage from measured profiles of guide-ways. The XY stage usually moves along its guide ways. The motion error of each stage has effect on 2D position errors of XY stages and affected mainly by profiles of guide-ways. To estimate 2D position error and flatness of stages, the profiles of guide-ways were measured and used in motion error estimation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1438-1441
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• 2005

To establish of standard technique of nano-length measurement in 2D plane, new AFM system has been designed. In this system, measurement uncertainty is dominantly affected by the Abbe error of XY scanning stage. No linear stage is perfectly straight; in other words, every scanning stage is subject to tilting, pitch and yaw motion. In this paper, an AFM system with minimum offset of XY sensing is designed. And XY scanning stage is designed to minimize rotation angle because Abbe errors occur through the multiply of offset and rotation angle. To minimize the rotation angle optimal design has performed by maximizing the stiffness ratio of motion direction to the parasitic motion direction of each stage. This paper describes the design scheme of full AFM system, especially about XY stage. Full range of fabricated XY scanner is $100um\times{100um}$. And tilting, pitch and yaw motion are measured by autocollimator to evaluate the performance of XY stage. Using this AFM system, 3um pitch specimen was measured. As a result, the uncertainty of total system has been evaluated.

• Korean Journal of Adult Nursing
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• v.16 no.3
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• pp.493-501
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• 2004

Purpose: The purpose of this study was 1) to classify the stage of adoption 2) to compare the decisional balance and confidence by stage of adoption 3) to identify factors influenced the stage of adoption for breast self exam. Method: A comparative study using a survey method with convenience sample of 143 women was used. Decisional balance and confidence was measured using the CHBMS-K. Stage of adoption for BSE was measured by a single item modified by the researchers based on the Rakowski et al (1992). Result: 1) The number of women in each stage of adoption for BSE was as follows; maintenance phase, 7.7% (n=11), action phase, 49.0% (n=70), contemplation phase, 35.0% (n=50) and pre- contemplation phase, 8.4%(n=12). 2) The mean difference in the decisional balance (F=4.32, p=.006) and confidence (F=13.85, p=.000) according to the stage of BSE adoption was statistically significant. 3) Prevention education and confidence accounted for 32% of variance in BSE. Conclusion: Assessment of decisional balance and stage of adoption for BSE can guide planning for cancer prevention education. We must educate women to have confidence in BSE. Further, it is important to urge women to continually practice BSE.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.96-103
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• 2006

To establish of standard technique of nano-length measurement in 2D plane, new AFM system has been designed. In the long range (about several tens of ${\mu}m$), measurement uncertainty is dominantly affected by the Abbe error of XY scanning stage. No linear stage is perfectly straight; in other words, every scanning stage is subject to tilting, pitch and yaw motion. In this paper, an AFM system with minimum offset of XY sensing is designed. And XY scanning stage is designed to minimize rotation angle because Abbe errors occur through the multiply of offset and rotation angle. To minimize the rotation angle optimal design has performed by maximizing the stiffness ratio of motion direction to the parasitic motion direction of each stage. This paper describes the design scheme of full AFM system, especially about XY stage. Full range of fabricated XY scanner is $100{\mu}m\times100{\mu}m$. And tilting, pitch and yaw motion are measured by autocollimator to evaluate the performance of XY stage. As a result, XY scanner can have good performance. Using this AFM system, 3um pitch specimen was measured. The uncertainty of total system has been evaluated. X and Y direction performance is different. X-direction measuring performance is better. So to evaluate only ID pitch length, X-direction scanning is preferable. Its expanded uncertainty(k=2) is $\sqrt{(3.96)^2+(4.10\times10^{-5}{\times}p)^2}$ measured length in nm.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.373-376
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• 2008

Industrial Steam Turbine first stage shell pressure is related to throttle flow. Theoretically, first stage shell pressure could, therefore, be measured and used as an index of turbine throttle flow. However, accurate flow measurements show that this pressure is not a reliable index of the actual flow. Data analysis of steam turbinessubjected to ASME acceptance tests shows that the use of first stage shell pressure as an index of throttle flow produced errors as large as 9.6 %. The mean of the errors was +2.2% with a standard deviation of ${\pm}$2.8 %. Applications that require an accuratedetermination of turbine steam flow, such as turbine acceptance testing, should, therefore, not rely on this method. Therefore, First stage shell pressure measurement serves as a valid and economical indicator of turbine throttle flow in cases where a high degree of accuracy in throttle flow measurement is not required but repeatability is desired, such as for boiler control. Generally speaking, Steam turbine first stage shell pressure may also be a very useful monitor of turbine performance when used with certain other turbine measurements.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.5
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• pp.295-303
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• 2008

The objectives of this study are to predict actual system performance and effective operating range of the 2-stage compression heat pump system using river water. An electronic expansion valve was applied to the simulation to analyze the effects of operating conditions on the system performance. The developed program was verified by comparing the predictions with the measured data. The results from the present model showed a good agreement with the measured data. In addition, the heat pump simulation was conducted by increasing condenser reservoir inlet temperature to investigate the benefits of the 2-stage compression over the 1-stage compression in the heating mode. The performance of the 2-stage compression cycle was better than that of the 1-stage compression when the inlet temperature of the condenser reservoir was higher than $40^{\circ}C$.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.167-173
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• 2004

The heterodyne He-Ne laser interferometer is the most widely used sensing unit to measure the position error. It measures the positioning error from the displacement of a moving reflector in terms of the wave length. But, the wave length is affected by the variation of atmospheric temperature. Temperature variation of 1$^\circ C$ results in the measuring error of 1ppm. In this paper, for measuring more accurately the position error of the ultra precision stage, the refractive index compensation method is introduced. The wave length of the laser interferometer is compensated using the simultaneously measured room temperature variations in the method. In order to investigate the limit of compensation, the stationary test against two fixed reflectors mounted on the zerodur$\circledR$ plate is performed firstly. From the experiment, it is confirmed that the measuring error of the laser interferometer can be improved from 0.34${\mu}m$ to 0.11${\mu}m$ by the application of the method. Secondly, for the verification of the compensating effect, it is applied to estimate the positioning accuracy of an ultra precision aerostatic stage. Two times of the refractive index compensation are performed to acquire the positioning error of the stage from the initially measured data, that is, to the initially measured positioning error and to the measured positioning error profile after the NC compensation. Although the positioning error of an aerostatic stage cannot be clarified perfectly, it is known that by the compensation method, the measuring error by the laser interferometer can be improved to within 0.1${\mu}m$.

• Journal of Korean Society of Water and Wastewater
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• v.17 no.4
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• pp.495-502
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• 2003

In order to modify incorrect flow data in the sewage system, the method using the stage-discharge relation and hydraulic characteristic curve of sewer pipe are applied. The modified data were verified with field measured data and the infiltration analysis using the modified data was carried out. When flowrate were measured using the flow-meter in fair weather, the stage data were comparatively consistent but velocity data were very poor for the most part. Therefore, it was recommended that sewage flowrate variation characteristic curve and infiltration were computed using the modified data on the basis of stage data. Especially, in the case of using the hydraulic characteristic curve, extrapolation results of the rainy season flowrate using regression curve on the basis of the data in fair weather were also reasonable.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.287-293
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• 2022

Radiographic left atrial dimension (RLAD) is a useful measurement to assess left atrial enlargement in dogs. There are studies on the use of RLAD on various breeds of dogs, but no study on a specific breed with myxomatous mitral valve disease (MMVD). This study was conducted to compare RLAD measurements in Maltese dogs with MMVD ACVIM stage B1 and B2, and also to investigate the correlation of RLAD with the LA:Ao ratio. A total of 29 Maltese dogs were the subjects of this study. Each dog was diagnosed with MMVD ACVIM stage B1 or B2 based on physical examination, thoracic radiography, and echocardiography. The vertebral heart size (VHS), RLAD, LVIDDn, and LA:Ao ratio were measured and compared to evaluate the differences. There were significant differences in the RLAD, LVIDDn, and LA:Ao ratio between dogs with MMVD ACVIM stage B1 and those with stage B2. There was a significant correlation between the LA:Ao ratio and both the RLAD and VHS measurements, but the correlation coefficient was higher for RLAD. The RLAD scores exhibited a significant difference between dogs with ACVIM Stage B1 and with those with B2, and these scores had a higher correlation with the LA:Ao ratio measured by echocardiography than with VHS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.975-978
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• 2007

This paper investigates stage acoustics in concert halls for ensemble performance in terms of stage support parameters. A concert hall with large stage area was selected. Objective measurements were carried out according to Gade's methods for investigating stage support (ST1). The sound field on the stage was evaluated using stage and audience acoustical parameters. According to the positions at stage, different acoustical characteristics were found. Higher ST1 and lower $IACC_{E3}$ were measured near side and rear stage walls. In case of conductor/soloist vs. orchestra player, objective measurement of acoustical parameters shows that early sound fields depend on the source-receiver distance but late sound fields depend on the location of side and rear walls. In addition, in-situ evaluation of the trio instrumentalists was carried out. Results show that ensemble is favored by higher early reflection of sounds and sound diffusion affecting ‘blending’ of their performance.