• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.11a
• /
• pp.269-270
• /
• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.131-132
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.471-472
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.9-10
• /
• 2009

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.1096-1101
• /
• 1992

In order tominimize fixing error of workpieces, circle, prismatic, sphere, cylindrical and sculptures types. Modification Rule by Indexing Table and Modification Rule by NC Program are developed for machining centers by using touch trigger probes. The Modification Rule by Indexing Table meas the alignment of workpiece to NC program through degree of freedoms of indexing table. The Modification Rule by NC Program is the alognment of NC program to workpiece ste-tp condition via the generation of NC progarm. A postprocessing module is alos developed for generating NC-part program(User Macro) to compensate for machining errors in end milling and boring processes. Developed method are verified by experiments.

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.7
• /
• pp.94-100
• /
• 2010

This paper describes the design and evaluation procedure of an ultra-precision rotary table for freeform generating machined tools. Design of the thrust and journal hydrostatic bearings and experimental evaluation of the table were performed. To get the compact size and less lost motion direct drive servomotor with ultra precision encoder. From the considered design, following performance were confirmed by experiment. The total stiffness of the prototype rotary table was 483.6 $N/{\mu}m$ and 97.6 $N/{\mu}m$ for axial and radial direction, respectively. Rotational accuracy of the table was investigated by capacitive sensor and reversal measurement technique, and 0.10 ${\mu}m$ radial direction and 0.05 ${\mu}m$ axial direction of the rotational accuracy were confirmed. The micro resolution of the table was also investigated with displacement of capacitive sensor, and $0.5/10000^{\circ}$ of micro resolution was confirmed. Index accuracy of the table was evaluated by the autocollimator and polygon mirror, and the $\pm0.39$ arcsec accuracy and $\pm0.16$ arcsec repeatability of the table were confirmed. Those are under the general requirements of ultra precision rotary tables for freeform generating machined tools.

• Journal of the Korean Home Economics Association
• /
• v.24 no.3
• /
• pp.43-50
• /
• 1986

This study is toidentify what makes people uncomfortable when people wear new shoes and to gain fundamental data for establishing shoe sizes. Data materal from the 16 measurement investigation conducted on 796 college girl students shows the following. 1) More than 96% of the subjects have experienced footache when they wore new shoes. It is significant that 45.76% of the subjects answered shoe width, especially pump-lining part cause them to feel more pain in their feet than any other measurement elements. 2) According to multiple correlation analysis to know which parts of feet determine shoe size, both multiple correlation coefficient of feet length to other parts of foot and joint girth to other parts of foot show the highest of R=0.93. 3) According to the ANOVA-tested result of estimated function when both foot-length-joint girth and foot length-joint girth-foot width are independent variables in each case, the level of α〈0.001 is very significant. 4) The comparision between KS G3116 adult women's shoe size establishment table and my table in this study reveals that the cases of more increased joint girth measurements than standard joint girth measurements in KS G 3116 table are easy to find.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.5
• /
• pp.124-130
• /
• 2000

For measuring out the submicron order straightness, a precision measuring device is developed in this paper. The device is constructed with a hydrostatic feed table and a capacitive type sensor which is mounted to the feed table. Straightness is acquired as substracting the motion error of feed table from the measured profile with probe. Motion error of feed table is simultaneously compensated upto 0.120${\mu}{\textrm}{m}$ of linear motion error and 0.20arcsec of angular motion error using the active controlled capillary. Reversal method and strai호t-edge is used fur estimating the measuring accuracy and from the experimental result, it is verified that the device has the measuring accuracy 0.030m. Also, through the practical application on the measurement of ground surface, it is confirmed that the device is very effective to measure the submicron order straightness.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.5 no.3
• /
• pp.178-197
• /
• 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

• Journal of Astronomy and Space Sciences
• /
• v.28 no.4
• /
• pp.311-317
• /
• 2011

Momentum changing actuators like reaction wheels and control moment gyros are generally used for spacecraft attitude control. This type of actuators produces force and torque disturbances. These disturbances must be reduced since they degrade the quality of spacecraft attitude control. Major disturbances are mainly due to static and dynamic imbalances. This paper gives attention to the reduction of the static and dynamic imbalance. Force/torque measurement system is used to measure the disturbance of the test reaction wheel. An identification method for the location and magnitude of the imbalance is suggested, and the corrections of the imbalance are performed using balancing method. Through balancing, the static and dynamic imbalance is remarkably reduced.