• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.1
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• pp.37-43
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• 1991

An efficient method for generating floor response spectra with the structure-equipment interaction effects is proposed. Floor response spectra are computed from a prescribed ground response spectrum by a random vibration approach. Transfer function of equipment response for earthquake excitation is constructed directly from the modal properties of the individual structures. The method also can account for the nonproportional damping characteristics of the combined system.

• ETRI Journal
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• v.35 no.1
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• pp.109-119
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• 2013

Static testing of analog-to-digital (A/D) and digital-to-analog (D/A) converters becomes more difficult when they are embedded in a system on chip. Built-in self-test (BIST) reduces the need for external support for testing. This paper proposes a new static BIST structure for testing both A/D and D/A converters. By sharing test circuitry, the proposed BIST reduces the hardware overhead. Furthermore, test time can also be reduced using the simultaneous test strategy of the proposed BIST. The proposed method can be applied in various A/D and D/A converter resolutions and analog signal swing ranges. Simulation results are presented to validate the proposed method by showing how linearity errors are detected in different situations.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.189-192
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• 2012

Underground structure construction in the downtown is very difficult despite the development of construction technology. We have been a lot of research in order to solve the problem, it was a remarkable achievement. But there are still many difficulties. This study is to analyze the construction technology to demolish the existing underground structures and to build new building applied topdown method at the same time. This technology was effective to suppress interference between the exsisting structure and new building. Therefore, this technology is expected to be able to be used in similar cases in the future.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.428-430
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• 2008

Dye-sensitized solar cell has many internal resistant components such as Pt counter electrode, $TiO_2$/dye/electrolyte, charge diffusion, sheet resistance of TCO. Among these, the resistance about the counter electrode can be reduced by increasing the roughness factor of Pt counter electrode. This causes the increase of fill factor and improvement of efficiency. And the amount of light reflection on the counter electrode also increases as the roughness factor goes up. In our experiment, we suggest a new deposition structure of Pt thin film that is a stepped-type structure. The more step lines are in the counter electrode, the more roughness factor is. As a result, we get the improvement of fill factor and efficiency by controlling the roughness factor of counter electrode.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.5
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• pp.462-467
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• 2009

Reduction of the structure-borne noise of the naval vessel is very important in order to reduce the underwater radiated noise of it. One of the important factors to reduce the structure-borne noise of the installed machine in a ship is the design of the foundation having sufficiently high mechanical impedance. In this paper, the mechanical impedance of the foundation for the fan-coil unit in a naval vessel is evaluated numerically according to variation of the thickness of the foundation. And also, the forced vibration analysis is conducted considering the dynamic property of the anti-vibration mount. Through the analysis results, it can be known that the dynamic property of the anti-vibration mount should be considered when the minimum level of the mechanical impedance of the foundation is set.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.170-176
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• 2008

The quantitative structure-activity relationship (QSAR) of a set of 35 flavonoid compounds presenting antioxidant activity was established by means of Genetic Algorithm-Multiple Linear Regression (GA-MLR) technique. Four-parametric models for two sets of data, the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity $(R^2=0.788,\;Q^2_{cv}=0.699\;and\;Q^2_{ext}=0.577)$ and scavenging activity of reactive oxgen species (ROS) induced by $H_2O_2 (R^=0.829,\;Q^2_{cv}=0.754\;and\;Q^2_{ext}=0.573)$ were obtained with low external predictive ability on a mass basis, respectively. Each model gave some different mechanistic aspects of the flavonoid compounds tested in terms of the radical scavenging activity. Topological charge, H-bonding complex and deprotonation processes were likely to be involved in the radical scavenging activity.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.67-67
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• 2011

Recently, Phthalocyanine dye has attentions due to their excellent photochemical properties and used to optical applications such as chemical sensors. And azo groups can change photochemical properties in the UV irradiation because their molecualr structure reverse cis-trans isomer and changes cooperative motion, aggregation and so on. In this study, we synthesized the azo compound between amino pyridine and phenol. this azo derivative used the combination with 3-nitro phthalonitrile and makes phthalocyanine structure through the synthesis with 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU), zinc acetate. Finally, we synthesized a new photoswiching dye zinc-phthalocyanine azo compound. This compound was studied by phothoswichiing phenomenon by UV irradiation and analyzed molecular aggregation through the SEM images.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.156-163
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• 2010

The brushless motor is getting widely applied to the automotive component with the advantage of the high efficiency, high reliability and etc.. Most of the motor applications require the low vibration and acoustic noise. The cogging torque is the one of the main cause of the noise and vibration. The step-skewed rotor is used to reduce the cogging torque. We analyze the characteristics of the step-skewed rotor and non skewed rotor with the same stator by using 2-dimensional FEM. And then we analyze the characteristics variation according to the rotor eccentricity. The prototype is made and tested. As the results, the step-skewed rotor structure reduce the cogging torque and local radial force but it is more sensitive to rotor eccentricity.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.59-64
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• 2006

The automation of hot rolling process requires the developments of several mathematical models for simulation and quantitative description of the industrial operations involved in order to achieve the continuously increasing productivity, flexibility and quality(dimensional accuracy, mechanical properties and surface properties). The mathematical modeling of hot rolling process has long been recognized to be a desirable approach to investigate rolling operating practice and design of mill requirement. To achieve this objectives, a new teaming method with neural network to improve the accuracy of rolling force prediction in hot rolling mill is developed. Also, Genetic Algorithm(GA) is applied to select the optimal structure of the neural network and compared with that of engineers experience. It is shown from this research that both structure selection methods can lead to similar results.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.11a
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• pp.238-244
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• 2004

In this study we have examined Copper and Nickel double metal layer on the synthetic fabrics by electroless chemical plating. We have focused on the shielding effect of the four kinds of woven and none-woven structure against electromagnetic fields. The shielding effectiveness of Copper and Nickel double metal layer showed between 90dB and 70dB, which are closely related to the fabric structure, that is cover factor and density. The more dense, The better shielding effect.