• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.9
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• pp.49-57
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• 1999

The fusion of fuzzy set theory and neural networks technologies have concentrated on applying neural networks to obtain the optimal rule bases of fuzzy logic system. Unfortunately, this is very hard to achieve due to limited learning capabilities of neural networks. To overcome this difficulty, we propose a new approach in which rough set theory and neuro-fuzzy fusion are combined to obtain the optimal rule base from input/output data. Compared with conventional FNN, the proposed algorithm is considerably more realistic because it reduces overlapped data when construction a rule base. This results are applied to the construction of inference rules for controlling the temperature at specified points in a refrigerator.

• Journal of the Korea Institute of Building Construction
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• v.11 no.1
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• pp.83-90
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• 2011

The purpose of this research is to investigate the effect of AFm formation on the stiffening process of cement paste. High and low alkali sulfate clinkers were used for the experiments. The flow and stiffening behavior of cement paste was investigated using modified ASTM C403 penetration resistance test and oscillatory shear rheology. X-ray powder diffraction (XRD) was used for phase identification associated with stiffening of the paste. It was found from the results that low alkali clinker mixture produced very strong premature stiffening whereas high alkali clinker mixture did not cause premature stiffening. This is because of the large amount of alkali sulfate present in the clinker. Addition of calcium and sodium chloride to the high alkali clinker mixture caused faster stiffening and set.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.1
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• pp.96-105
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• 1992

A study on the construction of a CAD/CAM system operated by 16 Bit PC basic language, for machining sculptured surface of die, was carried out. The system consists of 2 steps i.e., process for geometric modelling by wire frame and process for machining data generation. Geometric modelling for sculptured surface is made by the point data fitting, parallel sweeping, normal sweeping and linear connection of cross section curve. Machining data are gained by cutter off-set of geometric model data and machining carried out by DNC. This system is to be proved enough for rough cutting by actual machining experiment. But, for becoming a high level system, another method of cutter off-set has to be regarded and system must be reconstructed by another program language.

• Structural Engineering and Mechanics
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• v.4 no.4
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• pp.365-381
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• 1996

Stability equations that evaluate the elastic critical axial load of columns in any type of construction with sidesway uninhibited, partially inhibited, and totally inhibited are derived in a classical manner. These equations can be applied to the stability of frames (unbraced, partially braced, and totally braced) with rigid, semirigid, and simple connections. The complete column classification and the corresponding three stability equations overcome the limitations and paradoxes of the well known alignment charts for braced and unbraced columns and frames. Simple criteria are presented that define the concept of partially braced columns and frames, as well as the minimum lateral bracing required by columns and frames to achieve non-sway buckling mode. Various examples are presented in detail that demonstrate the effectiveness and accuracy of the complete set of stability equations.

• Transactions of The Korea Fluid Power Systems Society
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• v.7 no.1
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• pp.6-10
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• 2010

A measurement of very high torque for track drive unit in construction equipment is usually in difficulties due to the requirement of a torque meter with high capacity, and the limitation of geometry for an experimental set-up. To improve the troublesome problem, a new device was proposed, where a torque transmitted through the torque arm can be measured by load cells attached at each torque arm. The experimental set-up of the new device was carried out in order to measure the torque values for a mechanical feedback type planetary gear box, in which the power flow circulates itself in a closed-loop. The new device enables to measure torque values of 60,000Nm. Additionally, the measured values were estimated statistically in the aspect of their repeatability and reproducibility, so that an acceptable behaviour as a measuring device can be confirmed.

• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.193-207
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• 2001

When designing a test set, we need to consider constraints on items that are deemed important by item developers or test specialists. The constraints are essentially on the components of the test domain or abilities relevant to a given test set. And so if the test domain could be represented in a more refined form, test construction would be made in a more efficient way. We assume that relationships among task abilities are representable by a causal model and that the item response theory (IRT) is not fully available for them. In such a case we can not apply traditional item selection methods that are based on the IRT. In this paper, we use entropy as an uncertainty measure for making inferences on task abilities and developed an optimal item selection algorithm which reduces most the entropy of task abilities when items are selected from an item pool.

• Language and Information
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• v.2 no.2
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• pp.185-220
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• 1998

The purpose of this research is to propose a set of basic guidelines for the construction of English test suites, a set of basic guidelines for the construction of Korean test suites to objectively evaluate the performance of machine translation systems. For this end, we constructed 650 English test sentences, 650 Korean test sentences, and developed the statistical methods and tools for the comparative evaluation of the English-Korean machine translation systems. It also evaluates the existing commercial English-Korean machine translation systems. The importance of this research lies in that it will promote an awareness of the importance and need of testing machine translation systems within the Natural Language Community. This research will also make a big contribution to the development of evaluation methods and techniques for appropriate test suites for Korean information processing systems. The results of this research can be used by the natural language community to test the performance and development of their information processing systems or machine translation systems.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.629-634
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• 2002

Demands for the automatic measurement on angle and depth of equipment were arisen for the better construction in deep mixing method and grouting method. Civil, geotechnical, electronic, and communication experts worked together for the development of automatic measuring devices using wire and wireless transmitting-receiving set. The results on the development of automatic devices in an industrial installation will be presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.238-239
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• 2019

In this study, it was intended to confirm the possibility of using the Durometer in estimating the setting time by comparing the Proctor penetration resistance with the Durometer type A of hardness in concrete substituting CBS Dust. With the hardness of Durometer type A, it is expected to be used conveniently in the field of practice as it is determined to be about 18 HD for the initial determination and 31 HD for the end measurement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.160-161
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• 2015

Borosilicate glass can be used for improving neutron shielding of concrete. The well known expansion of borosilicate glass caused by expansion of mortar bar was can cause serious damage to the concrete. In this research, borosilicate glass was powdered to reduce the particle size similar to that of cement, and 20% cement replacement set was reduced expansion rate about 30%. But aggregate replacement set was damaged because of Alkali-Silica Reaction expansion.