• Proceedings of the KSR Conference
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• 2001.10a
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• pp.171-178
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• 2001

Air spring for railway rolling-stock is a part of secondary suspension system which play the role of supporting load, damping vibration. Recently, air springs are actively applied to railway rolling-stock to substitute coil spring with upgrading the manufacturing skill. This study is started to get the fundamental datum related to air spring for the purpose of developing the test draft for air spring. To analyze the performance of air spring, we conducted the simulation for railway rolling-stock applied air spring and tested train in convention lines. Thus, we have obtained useful datum to develop the test draft for air spring. Here, we describe some results.

• IE interfaces
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• v.4 no.2
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• pp.1-12
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• 1991

This paper deals with the development of a computer aided fixture planning system that automatically selects set-ups, set-up sequence and fixture design for prismatic parts. This study presents the hierarchical data structure for feature-based part model and the preprocessing procedure for the proposed system. The preprocessing procedure generates tools such as DDR(Degree of Dimensional Relationship), AMV(Admissible Misalignment Value) and the datum reference frame of each feature according to the proposed decision table. The proposed system is called AFIX(Automated FIXture planning system) which is implemented by using C language on the workstation. A case study for a cavity plate is presented to show the performance of the AFM.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.4
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• pp.68-75
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• 2003

This paper introduces the development of hydraulic cylinder with magnetic sensors detecting absolute and precise position for automation of excavator. The system which is developed can detect absolute position with a little displacement by using algorithm for recognizing datum points, 114 divider algorithm and high precision algorithm improved position precision. We alse evaluate the developed system under the load disturbance and add band pass filter to the previous's signal process circuit for the protecting magnetic sensors's saturation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.3 no.2
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• pp.11-17
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• 1985

In the three dimensional Cartesian Coordinate System such as the satellite geodesy the relationship of the geoid and the reference ellipsoid must be known. Therefore, the determination of geoidal heights is regarded as one of the most important problem in geodesy. This paper deals with determination of astro-geodetic geoid by the spherical surface polynomials interpolation method. The data that astronomical deflection of the vertical was published by National Geography Institute is applied. The map of geoidal heights is drawn out. This shows that Tokyo Datum have influenced on Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.1 no.2
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• pp.39-52
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• 1995

There are numerous mapping, charting, geodetic systems and electronic digital products defined in various local geodetic datum. It becomes a straight forward requirement to simplify the complexity by referencing all the products to a common reference globally. WGS-84 is well known as a state-of-the-art global reference system based on the use of data, techniques and technology available within American Defence Mapping Agency(DMA). Its parameters can be translated into more accurate maps, charts and geodetic positioning compared to others previously. Since Global Positioning System(GPS/NAVSTAR), which is asssociated with World Geodetic System(WGS-84)in reference frame, has been widely used, the unified geodetic system has been required for GPS users in many fields.

• Journal of Korean Society for Geospatial Information Science
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• v.9 no.2 s.18
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• pp.63-71
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• 2001

GPS allows a user with an appropriate receiver to obtain their position anywhere on the Earth's surface. The use of GPs has highlighted the shortcomings of national reference systems, and many countries are in the process of establishing new geodetic frameworks in order to overcome these shortcomings. Korea National Geography Institute has established a new geocentric datum and presented the its time frame for implementation. In this paper, I studied the considerable matters of digital mapping authority and users for converting the geodetic datum and coordinate system and suggested the steps of public relations for GIS users.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.2
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• pp.99-107
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• 2000

The objective of this study are to compare the development of compressive strength of epoxy mortars used as repairing materials with respect to maturity , and to propose a model predicting strength development of epoxy mortars. A series of tests are carried out for the hardener contents of 30, 40 and 50 percentage of epoxy resin and compressive strengths are measured at the age of 6, 12, 24, 72, 120 and 168 hours respectively under the cure temperature of 0, 10, 20 and 3$0^{\circ}C$. The datum temperature is estimated by measured strengths, and the maturity is calculated with the estimated datum temperature. The compressive strength of epoxy mortars can be predicted by regression analysis from the maturity-compressive strength relationship.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.S1
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• pp.43-43
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• 1996

• Proceedings of the Korea Water Resources Association Conference
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• 1999.05a
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• pp.159-164
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• 1999

• Proceedings of the Korea Water Resources Association Conference
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• 1999.05a
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• pp.183-188
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• 1999