• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.339-344
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• 1995

In the design of ductile moment-resisting frames (DMRFs) following the strong column-weak beam dsign philosophy, it is desirable that the joint and column remain essentially elastic in order to insure proper energy dissipation and lateral stability of the structure. The joint has been identified as the "weak link" in DMRFs because any stiffness or strength deterioration in this region can lead to substantial drifts and the possibility of collapse due to P-delta effects. Moreover, the engineer is faced with the difficult task of detailing an element whose size is determined by the framing members, but which must resist a set of loads very different from those used in the design of the beams and columns. Four 2/3-scale beam-column-slab joint assemblies were designed according to existing code requirements of ACI 318-89, representing interior joints of DMRFs with reinforced high strength concrete. The influence on aseismic behavior of beam-column joints due to monolithic slab, has been investigated.estigated.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.426-430
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• 2005

The fiber-optic interferometer which is a powerful application for nondestructive measurement techniques has many advantages such as capability of making portable system, easy optical arrangement, low optical loss. In spite of these advantages, this system has an environmental sensitivity of thermal drifts and vibrations. Against environmental perturbations and nonlinear characteristic of phase modulator, the accurate and fast ${\pi}/2$ phase stepping has been achieved by using zero-crossing detection. CCD camera trigger signal is generated at the 4 zero-crossing points. Our System has achieved up to 100 Hz of image capture speed and 0.6 mrad of accuracy of phase stepping, accuracy.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.588-590
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• 2006

Recently, many on-line approaches to instrument channel surveillance (drift monitoring and fault detection) have been reported worldwide. On-line monitoring (OLM) method evaluates instrument channel performance by assessing its consistency with other plant indications through parametric or non-parametric models. The heart of an OLM system is the model giving an estimate of the true process parameter value against individual measurements. This model gives process parameter estimate calculated as a function of other plant measurements which can be used to identify small sensor drifts that would require the sensor to be manually calibrated or replaced. This paper describes an improvement of auto-associative kernel regression by introducing a correlation coefficient weighting on kernel distances. The prediction performance of the developed method is compared with conventional auto-associative kernel regression.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.253-255
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• 2004

The mining-related damages such as ground subsidence, acid mine drainage(AMD), and deforestation in the abandoned underground coal mine areas become an object of public concern. Therefore, the system to manage the miningrelated damages is needed for the effective drive of rehabilitation activities. The management system for Abandoned Underground Coal Mine using GIS includes the database about mining record and information associated with the mining-related damages and application programs to support mine damage prevention business. Also, this system would support decision-making policy for rehabilitation and provide basic geological data for regional construction works in abandoned underground coal mine areas.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.143-149
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• 2004

In this paper, an automation model for drift design of high-rise buildings using resizing algorithms is proposed. Drift, in the model, includes the maximum lateral displacement at the top and inter-story drifts of a high-rise building subjected to both wind and seismic load. Resizing algorithms for high-rise buildings in various systems and material developed in previous researches are used as a drift control module. As an input to drift control algorithms, member forces for calculation of member displacement participation factors are obtained from commonly-used commercial softwares. The automation model is composed of 4 modules: initial modeling, drift control, stress check, and final verification modules. Each module in the model is described in detail in this paper.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.30-33
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• 2006

The purpose of this research is to study the seismic behavior of interior column-slab connections with different column aspect ratio, when subjected to combined gravity and cyclic lateral loading. The control specimen had square column, while the other specimens had rectangular column with aspect ratio of 0.5 and 2.0. From the test results, all of the specimens sustain lateral drifts as high as 4% with no more than a 20% decrease in peak lateral load capacity. And it appears that KBC Code(2005) procedure may be unconservative for connections with different column aspect ratio.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.9
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• pp.388-394
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• 2003

Many toxic pesticides as aqueous-base sprays are dispensed for protection of food crops from pests into farm fields. When dispensed with conventional nozzles, a large portion of the spray is often lost by airborne drifts of droplets away and lack of deposition onto the plants due to rapid gravitational settling of droplets to the soil beneath. And target deposition efficiencies poorer than 20％ are often encountered in agricultural pesticides. An electrostatic spraying technology offers a very favorable means to increasing pesticides droplets deposition onto biological surfaces of living crops. In this paper a corona type spray nozzle, utilizing a set of corona charging devices and a pulsed droplet-charging voltage applied, has been proposed and tested its potential experimentally. As a result, it exhibits a large current deposition of aqueous pesticide sprays on the sensing target, which, however, promise to be as one of the effective electrostatic spraying nozzle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.214-219
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• 1997

We propose a new scheme of high-resolution heterodyne interferometer that employs the two-axial mode He-Ne laser with an inter-mode beat frequency of 600-1000 MHz. An electronic RF-heterodyne circuit lowers the beat frequency down to 5 MHz, so that the phase change of the interferometer output is precisely measured with a displacement resolution of 0.1 nanometer without significant loss of dynamic bandwidth. A thermal control scheme is adopted to stabilize the cavity length with aims to suppress frequency drifts caused by the phenomena of frequency pulling and polarization anisotropy of the two-axial mode laser to a stability level of 2 parts in $10^9$. The two-axial mode HeNe laser yields a high output power of 2.0 mW, whlch allows us to perform multiple measurements of up to 10 machine axes simultaneously.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.7
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• pp.914-920
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• 2003

In this paper, we deal with two drift compensation algorithms of acceleration sensor for measuring the galloping on power transmission line. Firstly, the block diagram of galloping measurement system is given and a galloping model is presented. Secondly, two compensation algorithms, a simple compensation and a period compensation, are proposed. A simple compensation algorithm uses the drifts of velocity and distance at fixed periods, so it is useful for constant drift case. Next, a period compensation algorithm can compensate a periodic drift. This algorithm uses the previous measured data and compensated data for constant period, where the period is obtained by FFT method. Lastly, the effectiveness of proposed algorithms is verified by comparing between two algorithms in simulation, and its characteristics and the drift error bound are shown, respectively.

• Earthquakes and Structures
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• v.3 no.6
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• pp.853-867
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• 2012

In this paper, a new type of passive energy dissipating system similar to added damping and stiffness (ADAS) and triangular added damping and stiffness (TADAS) is proposed and implemented in the analytical model of a building with hybrid structural system in the structure's base which we call it; Telescopic column. The behavior and performance of a high rise R.C. structure equipped with this system is investigated and compared with conventional base isolation systems such as rubber isolator bearings and friction pendulum bearings. For this purpose a series of ground acceleration records of the San Fernando, Long Beach and Imperial Valley earthquakes are used as the disturbing ground motions in a series of numerical simulations. The nonlinear numerical modeling which includes both material and geometric nonlinearities were carried out by using SAP2000 program. Results show suitable behavior of structures equipped with telescopic columns in controlling the upper stories drifts and accelerations.