• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.707-712
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• 1996

Growth and changes of electronically conducting polypyrrole (PPy) in the form of thin films polymerized on metal electrodes were investigated by electrochemical and in situ three-parameter ellipsometry methods at the wavelength of 632.8 nm. Although the optical equations produced multiple sets of solution, it was possible to determine a unique set of thickness and the optical constants of a film by auxiliary measurements and/or physical reasoning. The changes in the thickness and the optical properties of the polymers during polymerization and electrochemical oxidation/reduction was successfully followed by the three-parameter ellipsometric technique. The optical properties of the polymers continuously changed as the film grew. The imaginary part of the refractive index of polypyrrole seemed to be dominantly determined by the existence of an absorption band around the visible range.

• Journal of KSNVE
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• v.7 no.3
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• pp.511-519
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• 1997

For a number of years it has been known that flexural vibration in a beam and plate can be damped by the application of layer of damping (viscoelastic) material that is in turn constrained by a backing layer or foil. In this study, a quantitative analysis of damping of the sandwich beam has been performed by using impact test. The damping is characterized by the loss factor .etha. in which the damping is normalized by imaginary part of the complex bending stiffiness of the beam. Results show that the relative thickness of the sandwich beam gives more effect on the riatural-frequencies and loss factor than the variation of width does. It is also shown that the Ross-Kerwin-Ungar equation and impact test can be effectively used to identify the damping characteristic of the sandwich beam and viscoelastic material.

• Journal of the Korean Home Economics Association
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• v.31 no.2
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• pp.81-96
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• 1993

The purpose of this study is to investigate how external pressures to remain married and alternative attractions to a marriage influence the relationship between marital satisfaction and marital stability. A total of 228 married women in Seoul responded to structured questionnaires. The major findings are as follows; 1. While the marital satisfaction is positively associated with the marital stability, the alternative attractions to a marriage are negatively associated with the marital stability. But there is no significant correlation between external pressures to remain married and marital stability. 2. The relationship strength between marital satisfaction and marital stability according to the level of external pressures to remain married and actual alternatives to a marriage is not appeared significant difference. 3. When the external pressures to remain marred are low and the imaginary alternatives to a marriage are low, marital satisfaction is the most powerful predictor of marital stability. 4. Whether wife has a job and marital satisfaction affected the marital stability independently.

• Journal of Ocean Engineering and Technology
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• v.8 no.2
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• pp.80-92
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• 1994

The dynamic response characteristics of a floating ocean city are examined for presenting the basic data for the design of huge offshore structures supported by a large number of floating bodies in waves. The numerical approach which is accurate in linear system is based on combination of a three dimensional source distribution method, wave interaction theory and the finite element method of using the space frame element. The hydrodynamic interactions among the floating bodies are taken into account in their exact form within the context of linear potential theory in the motion and structural analysis. The method is applicable to an arbitrary number of three dimensional bodies having any individual body geometries and geometrical arrangement with the restriction that the circumscribed, bottom-mounted. Imaginary vertical cylinder for each body does not contain any part of the other body. The validity of this procedure was verified by comparing with experimental results obtained in the literature.

• Journal of Power Electronics
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• v.9 no.5
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• pp.718-725
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• 2009

To get instantaneous reference data in a single power system with vector space phasors, the instantaneous load current is adopted as a phase and another new signal, which is delayed through filtering by the phase-delay property of a low-pass filter, is used as the secondary phase. Because the two-phases have a different phase, the instantaneous value of the harmonic current can be obtained without a time-delay in calculation. The reference voltage is created by multiplying the coefficient k by the compensation current using the rotating reference frame synchronized with the source-frequency. To verify the validity of the proposed control method, experiments are carried out on a prototype of the single-phase hybrid active power filter system.

• Korean Journal of Head & Neck Oncology
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• v.26 no.1
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• pp.45-47
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• 2010

Accessory tragus is an uncommon congenital anomaly of the external ear. The tragus derives from the first branchial arch. The accessory tragus can be found along the entire course of embryonic migration. Usually it appears as a small papules arising near the tragus, but rarely, along an imaginary line drawn back from the tragus to the angle of the mouth, or along the anterior edge of the sternocleidomastoid muscle and the sternoclavicular region. We experienced a case of accessory tragi on the suprasternal region in an 9 year-old-boy.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.210-217
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• 1999

This paper deals with the analysis for column shortening of RC frame structure considering the construction sequences. The time-dependent effects of concrete are taken into consideration in this study to simulate the actual structural behavior. The stiffness matrix of a beam element is derived on the bases of the layer approach, dividing a section with imaginary layers. Creep and shrinkage strains at each layer are calculated by using the first-order algorithm based on the expansion of creep compliance. Finally, the correlation studies with the purpose of analyzing the time-dependent behavior of building structure are conducted using the analytical model proposed in this study.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.6 s.237
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• pp.730-736
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• 2005

It has been reported that the interacting multiple jet flames of propane fuel are not extinguished even at the choking velocity at the nozzle exit if eight small nozzles are arranged along the imaginary circle of $40{\sim}72$ times the diameter of single nozzle. In this research, experiments were conducted to know the NO and CO emission characteristics of the interacting flames. Measurements along the centerline of the flame revealed that decrease in CO concentration was followed by the NO decrease and $O_2$ increase. It was found that interacting flame emitted less NO than that of similar area single jet flame. Also, NO emission of partially premixed interacting flame was decreased up to $17\%$ of that of non-premixed multiple jet flame. Though the mechanism of the NO reduction was not clear from this experiment, it's been shown that partially premixed multiple jet flames could be used to achieve clean and highly stable combustion.

• Journal of Power Electronics
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• v.11 no.6
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• pp.922-930
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• 2011

In this paper, two radial basis function neural networks (RBFNNs) are used to dynamically identify harmonics content in converter waveforms based on the p-q (real power-imaginary power) theory. The converter waveforms are analyzed and the types of harmonic content are identified over a wide operating range. Constant power and sinusoidal current compensation strategies are investigated in this paper. The RBFNN filtering training algorithm is based on a systematic and computationally efficient training method called the hybrid learning method. In this new methodology, the RBFNN is combined with the p-q theory to extract the harmonics content in converter waveforms. The small size and the robustness of the resulting network models reflect the effectiveness of the algorithm. The analysis is verified using MATLAB simulations.

• Iberoamérica
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• v.14 no.2
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• pp.119-145
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• 2012

This paper deals with the study of how the 'birth' of Brazil happened and how the European utopianism was represented in Brazilian Informative Literature of the sixteenth century, that is, the first literary manifestations of Brazil. There were at that time the Renaissance humanism and the scientific development that encouraged dozens of illustrious navigators for new discoveries ultra-seas, like Christopher Columbus who discovered America. Writings such as Letter to King Manuel of Pero Vaz de Caminha, had mostly an intention to inform Europeans about climates, indians and possibility to discover gold or silver. Main narrative characteristics were uncertainty and exageration, which ironically helped to attract more discoveries and explorations in the New World. Americo Vespucio's Mundus Novus inspired Thomas More to write Utopia, in which the author described through a Portuguese sailor the ideal but unrealizable society. Utopianism regarding the imaginary island of 'Brazi', well known among Europeans since long ago, may have influenced the current name of the country: 'Brazil'. On the other hand, utopianism shown in Brazilian Informative Literature worked as a justification for Europeans to explore and colonize the New World.