• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.205-213
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• 2008

The objective of this study is to evaluate the yield stress of SM570TMC CFT column subject to axial force. These columns were evaluated and compared by statistical tests, during which the displacements and axial loads of column specimens were measured. Test results showed that the yield stress of CFT columns under axial load could be predicted using the previously proposed the yield stress of steel columns.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.28-35
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• 2017

In this study, specimens of rigid frame joint were produced by integrating joints with adhesive and other specimens were produced by inserting a wooden gusset integrated with a column member into a slit-processed beam member and joining them with pins. Then the moment resistance performances of the specimens were examined. For the wooden gusset, a GFRP-reinforced wooden gusset was used. The calculation results of perfect elasto-plasticity for the frame specimens for which a GFRP-reinforced wooden gusset was inserted into and joined with the slit-processed beam member by pins were 20-80% lower compared to the control group which consisted of steel plate-inserted frame specimens. The rigid frame specimens for which the column and beam members have been integrated with adhesive showed almost no initial residual transformations, as well as 38% greater initial rigidity and 41% greater plasticity compared to the steel plate-inserted joint.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.789-799
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• 1998

The purpose of this study is to propose the prototypes of bolted end plate moment connection between CFT column and H-beam sections. Nine different types of bolt are designed in this study. The shapes of those bolt are straight. bent, hooked or stud-type. The end plate moment connection between CFT column and H-beam sections which are jointed by those bolts are studied experimentally to compare their performances. The simple beam bending tests are carried out to investigate the structural behavior of beam-to-column connections. The experimental results show that some of the bolted end plate connection types have quite good performance in the structural behavior but still have a lot of week points to be solved for the efficiency of construction.

• Journal of Educational Research in Mathematics
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• v.13 no.4
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• pp.495-506
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• 2003

In this study, 1 investigated some properties on the special hyper-dimensional figures made by the principle of the performance of equivalent forms representation. I supposed 2 definitions on the making n-dimensional figure : a cone type(hypercube) and a pillar type(simplex). We can explain that there exists only 6 4-dimensional regular polytopes as there exists only 5 regular polygons. And there are many hyper-dimensional figures, they all have sufficient condition to show the general Euler' Characteristics. And especially, we could certificate that the simplest cone type and pillar types are fitted to Pascal's Triangle and Hasse's Diagram, each other.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1540-1546
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• 2000

Recently, force measurement systems are commonly used in many industrial fields and the precision of the measurement system is getting more important as the industry needs more precise tools and in struments to make high quality products. However, a high precision force measurement system is hard to make unless we know precisely the causes, quality and quantity of measurement errors in advance. In this work, many possible mechanical causes of measurement errors are reviewed including ratio of length to diameter of sensing part, radius of contact area, radius of bearing part, ratio of material properties and change of boundary conditions. Also, the measurement errors are analyzed by nonlinear finite element method and the nonlinear behavior of the errors are investigated. The results can be used to design force measurement systems and expected to be very useful especially for compact type load cells.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.432-436
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• 1999

The development of Electromagnetic Communication technology have made our life abundant. However, the countermeasure of EMI(Electromagnetic Interference) are more important socially as increase of a main cause on electromagnetic waves occurrence. It is required that the absorbing ability of an electromagnetic wave absorber is above 20 dB, the bandwidth of which is required from 30 MHz to 1,000 MHz for satisfying the international standard about EMI and also will be required from 30 MHz up to 5,000 MHz in the bandwidth. In this paper, we proposed the square projection type absorber satisfying the above requirements and carried out broadband design using the equivalent material constants method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.5
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• pp.403-410
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• 2009

In this paper, damping coefficients and effective masses of tuned liquid-type column dampers were quantitatively evaluated based on experimental results by using system identification technique. First, shaking table tests were performed for two types of tuned liquid-type column dampers. Then, the dynamic characteristics of dampers used in this study were experimentally grasped from harmonic wave excitation testing results of the dampers with various water level. Finally, damping ratios and effective masses of the dampers with varying water level were quantitatively evaluated from minimizing the errors between numerical and experimental results. It was confirmed from system identification results that damping ratio and effective mass are decreased as the water level of dampers is increased.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.601-607
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• 2003

The column type is used as the sensing element of the load cell to measure the large force in the range of 10$^4$~ 10$^{7}$ N. However. it is not easy to handle the load with large capacity due to its size. It is, therefore, necessary to design a compact load cell with a low aspect ratio. Thus this paper showed the characteristic evaluation of compact load cell with respect to the shape of supporting plate. The supporting plate of the load cell was an annular type with inner(D$_{i}$) and outer(D$_{o}$) diameters. Using the strain distribution obtained from FEM. the supporting plate was designed to get the stable output voltage of the load cell. The three designed supporting plates were manufactured, and the result of characteristic experiment of the load cell, using the 10 MN hydraulic force standard machine, was compared with FEM.M.M.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.754-758
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• 2002

According to the enlargement of production facilities and structures, the requirements of high-capacity load cells are increased for monitoring the process conditions in many fields. Generally, however, the accuracy of the column-type high-capacity load cells is not enough due to the geometric nonlinearity. It is supposed to result from the fact that the whole spring element is under high-level stress for the uniform strain field. In this paper, a new shape of spring element is developed which utilizes the stress concentration. As a design criterion, an object function which quantifies the degree of nonlinearity is defined and optimized by use of response surface modeling. As a result, the weight of the spring element is reduced shout 50% in comparison to the conventional shape. The bonding positions of stain gages are found. which show theoretically zero geometrical nonlinearity, while the ratio of overload protection is reduced from 130% to 125% Also it is shown that the response surface method is very efficient in the optimization approach by use of FEM.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.171-172
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• 2011

In this research, we discuss the process of analyzing the solution of four-peg tower of Hanoi using protocol analysis technique, and of developing decision trees from the analyzed contents. For these, we design and implement a computer program that can simulate four-peg tower of Hanoi. The implemented program generates a certain regular-to-regular tower of Hanoi problem, let a user to solve the problem, and records the solution process. From the process by the implemented program and the recorded protocol, we can build the decision tree for the solution. We expect this research can contribute to find a non-optimal solution for n-peg tower of Hanoi.