• Journal of IKEEE
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• v.16 no.1
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• pp.34-44
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• 2012

This paper proposes a practical compensation method by using digital signal processing over the creep error which is representative in strain gauge loadcell. The signal compensation method carry out the simulation by deciding compensation constant (time constant) and coefficient measuring the loadcell output response. Then, compensation constant and coefficient are stored on the microprocessor. By using calculated on microprocessor creep error compensation values, weighting value is showed as a digital signal by reducing error values measured through output signals of loadcell. In addition, we apply error compensation method in order to have a dedicated software for loadcell electronic scale. This technique is useful because it has great influence on error rate reduction that has been produced by conventional electronic scales (0.03%). As a result our technique gives better accuracy (0.01%~0.003%) as what is given by digital electronic scale, while it has less complex operation processing.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.161-170
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• 1999

The KLCC Petronas Tower 2, one of the world tallest twin reinforced concrete towers constructed in Kuala Lumpur, Malysia, was instrumented during construction for the measurement of vertical time-dependent deformation of columns and corewall. Field measurements were made by means of vibrating wire strain gauges at the corewall, tower and bustle perimeter columns at selected floor levels of the building. Parallel to this observation, laboratory tests were performed on concrete cylinders made in the field in order to obtain the variations of concrete compressive strengths, elastic moduli, strains of creep and shrinkage with time. Monitored vertical deformations are in a good agreement with the prediction based on actual construction sequence and concrete properties from laboratory tests, as well as the analytical results reflected in actual column compensation of the building.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.208-215
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• 2018

The causes of column shrinkage and the codes that have been studied up to now are discussed. The documents mentioned in the code deal with the drying shrinkage, creep, compressive strength and elastic modulus of the specimen, and the elastic deformation calculated from the structural analysis. However, the deformation due to the temperature caused by the long term monitoring is less than that caused by the factors generated by the previous studies. In the previous studies, it was found that dehydration shrinkage, creep, and elastic deformation were not considered for temperature-induced deformation, while for the specimen experiments, the temperature-related items were replaced with the humidity-related terms The compensation value by the proposed equation showed error of 4.9 mm in the upper direction and 1.0mm in the lower direction when calculating column shortening, and it was found that its value by the proposed equation almost coincided with the measurement value in Site. Therefore, it is necessary to further study the temperature that can be omitted in calculating the existing column shortening, to consider the influence factors, and to supplement the criteria for the temperature measurement of the structure as well as the specimen tests.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.397-402
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• 1998

The objectives of this paper are to estimate differential column Shortening and to determine appropreate compensation amount in 52 story Amatapura Apartment in Indonesia. for this, a computer program based on PCA and CEB-FIP code is developed. The results show that Elastic and Creep strain are the main factors of column shortening and the maximum differential shortening is appeared near the middle of the building height. The results between field survey and estimation have some difference, the most influential factor of the difference can be lateral restraints provided by horizontal members, which cannot be handled in this developed program. Hence introducing the modification factors from various field survey, this program can be used properly in design and construction procedures.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.475-480
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• 1997

Highrise concrete buildings are very sensitive to cumulative and differential shortening of their vertical element such as wall and columns. Inelastic deformation due to creep and shrinkage consist of various factors and load history af actual building is very complicated. Therefore, for the accurate prediction and compensation of axial shortening, special efforts in design and construction phase are required to ensure long-term serviceability and strength requirement. In this paper, axial shortening estimation and compensation procedure is presented, which utilized experimentally determined concrete properties and preliminary load history and computerized approach, in case of Plaza Rakyat office tower, 79-story reinforced concrete building under construction in Malaysia.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.258-266
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• 1996

The purpose of this study is to make a reasonable correction in construction stage through exact prediction of long-time differential column shortening that occurs in the high-rise RC building. For this, a self-developed program adopted PCA code is used to predict differential column shortening with sequential loading process. Using this program, the amount of the different column shortening of Amatapura Apartment in Indonesia is predicted and the effect is analyzed. From the result, the major factor affecting the shortening amount in columns is elastic strain and the effect of shrinkage is very small rather than creep. And maximun differential column shortening is appeared near the middle of the building.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.86-94
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• 1993

In heavy industries forces which are exceeding the range of available force standard machines have to be measured. Force measuring system using build-up procedure can be applied to measure large forces efficiently. In this study strain gage type force sensors are designed and fabricated, and the build-up force measuring system with 4.5 MN capacity using the developed force sensors is 0.03% or less over the range of 600 kN .approx. 1.5 MN and the force measuring system is less than 0.06% or less over the range of 500 kN .approx. 4.5 MN.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.291-298
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• 2002

Recently, construction of reinforced concrete tall buildings is widely increased according to the improvement of material quality and design technology. Therefore, differential shortenings of columns due to elastic, creep, and shrinkage have been an important issue. But it has been neglected to predict the Inelastic behavior of RC structures even though those deformations make a serious problem on the partition wall, external cladding, duct, etc. In this paper, analysis system for prediction and compensation of the differential column shortenings considering time-dependent deformations and construction sequence is developed using the objected-oriented technique. Developed analysis system considers the construction sequence, especially time-dependent deformation in early days, and is composed of input module, database module, database store module, analysis module, and analysis result generation module. Graphic user interface(GUI) is supported for user's convenience. After performing the analysis, the output results like deflections and member forces according to the time can be observed in the generation module using the graphic diagram, table, and chart supported by the integrated environment.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.09a
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• pp.233-241
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• 2004

A new alloy definition will be presented concerning increasing demands for the board level reliability of miniaturized interconnections. The damage mechanism for LFBGA components on different board finishes is not quite understood. Further demands from mobile phones are the drop test, characterizing interface performance of different package constructions in relation to decreased pad constructions and therefore interfaces. The paper discusses the characterization of interfaces based on SnPb, SnPbXYZ, SnAgCu and SnAgCuInNd ball materials and SnAgCuInNd as solder paste, the stability after accelerated tests and the description of modified interfaces strictly related to the assembly conditions, dissolution behavior of finishes on board side and the influence of intermetallic formation. The type of intermetallic as well as the quantity of intermetallics are observed, primaliry the hardness, E modules describing the ability of strain/stress compensation. First results of board level reliability are presented after TCT-40/+150. Improvement steps from the ball formulation will be discussed in conjunction to the implementation of lead free materials In order to optimize ball materials for area array devices accelareted aging conditions like TCTs were used to analyze the board level reliability of different ball materials for BGA, LFBGA, CSP, Flip Chip. The paper outlines lead-free ball analysis in comparison to conventional solder balls for BGA and chip size packages. The important points of interest are the description of processability related to existing ball attach procedures, requirements of interconnection properties and the knowledge gained the board level reliability. Both are the primary acceptance criteria for implementation. Knowledge about melting characteristic, surface tension depend on temperature and organic vehicles, wetting behavior, electrical conductivity, thermal conductivity, specific heat, mechanical strength, creep and relaxation properties, interactions to preferred finishes (minor impurities), intermetallic growth, content of IMC, brittleness depend on solved elements/IMC, fatigue resistance, damage mechanism, affinity against oxygen, reduction potential, decontamination efforts, endo-/exothermic reactions, diffusion properties related to finishes or bare materials, isothermal fatigue, thermo-cyclic fatigue, corrosion properties, lifetime prediction based on board level results, compatibility with rework/repair solders, rework temperatures of modified solders (Impurities, change in the melting point or range), compatibility to components and laminates.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.09a
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• pp.211-219
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• 2004

A new alloy definition will be presented concerning increasing demands for the board level reliability of miniaturized interconnections. The damage mechanism for LFBGA components on different board finishes is not quite understood. Further demands from mobile phones are the drop test, characterizing interface performance of different package constructions in relation to decreased pad constructions and therefore interfaces. The paper discusses the characterization of interfaces based on SnPb, SnPbXYZ, SnAgCu and SnAgCuInNd ball materials and SnAgCuInNd as solder paste, the stability after accelerated tests and the description of modified interfaces stric시y related to the assembly conditions, dissolution behavior of finishes on board side and the influence of intermetallic formation. The type of intermetallic as well as the quantity of intermetallics are observed, primaliry the hardness, E modules describing the ability of strain/stress compensation. First results of board level reliability are presented after TCT-40/+150. Improvement steps from the ball formulation will be discussed in conjunction to the implementation of lead free materials. In order to optimize ball materials for area array devices accelareted aging conditions like TCTs were used to analyze the board level reliability of different ball materials for BGA, LFBGA, CSP, Flip Chip. The paper outlines lead-free ball analysis in comparison to conventional solder balls for BGA and chip size packages. The important points of interest are the description of processability related to existing ball attach procedures, requirements of interconnection properties and the knowledge gained the board level reliability. Both are the primary acceptance criteria for implementation. Knowledge about melting characteristic, surface tension depend on temperature and organic vehicles, wetting behavior, electrical conductivity, thermal conductivity, specific heat, mechanical strength, creep and relaxation properties, interactions to preferred finishes (minor impurities), intermetallic growth, content of IMC, brittleness depend on solved elements/IMC, fatigue resistance, damage mechanism, affinity against oxygen, reduction potential, decontamination efforts, endo-/exothermic reactions, diffusion properties related to finishes or bare materials, isothermal fatigue, thermo-cyclic fatigue, corrosion properties, lifetime prediction based on board level results, compatibility with rework/repair solders, rework temperatures of modified solders (Impurities, change in the melting point or range), compatibility to components and laminates.