• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.17-20
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• 2009

Available daylight in inside offers comfortable view environment, and psychological and physical advantages to people in a room. Architecture design has need of daylight prediction for reflection efficiently daylight. But it is difficult to predict the illuminance values in daylight system. Using various lighting simulation software is easy and simple, but we can find different results under the same conditions. This study compares with illuminance values from simulation (Lightscape 3.2, RELUX 2007, RADIANCE 3.9) and Mock-up experiment with the same space and parameter of daylight (location of space and window, date, time and sky condition).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.255-258
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• 2006

In this paper, a novel physical structure for planar spiral inductors is proposed. The spiral inductors were designed and fabricated on multi-layered substrate Bragg-reflector/silicon (BR/Si) wafer. The impacts of multi-layered structure substrate and pattern on characteristics of inductor were studied. Experimental results show that the inductor embedded on Bragg reflector/silicon substrate can achieve the best improvement. At 0.4-1.6 GHz, the Bragg reflector seems to significantly increase the $S_{11}-parameter$ of the inductor.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.43-50
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• 2007

A range-frequency interference pattern is analyzed in the course of the propagation of ship noise in shallow water. It has been shown to exhibit striated bands of intensity maxima and minima in the spectrogram. The slope of the striations is an invariant of the modal interference and is described by a waveguide invariant parameter $\beta$. It turns out that this interference pattern is useful for identifying the physical properties of the waveguide such as seabed properties. In this article, the interference pattern is analyzed using image processing techniques to produce the distribution of the beta and the effects of sediment types and geoacoustic parameters on beta distribution are examined and characterized by moments of the distributions.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.9
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• pp.33-42
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• 1998

If a ship diesel engine is operated by consolidated control with Controllable Pitch Propeller(CPP), the minimum fuel consumption is achieved together with the demanded ship speed. For this, it is necessary that the ship is operated on the ideal operating line which satisfies the minimum fuel consumption and that the pitch angle of CPP and throtle valve angle are controlled simultaneously. In this point of view, this paper presents a controller design method for a ship propulsion system with CPP based on the decoupling control theory. To do this, Linear Matrix Inequality(LMI) approach is introduced for the control system to satisfy the given $H_\infty$ control performance and robust stability in the presence of physical parameter perturbations. The validity and applicability of this approach are illustrated by simulation in the all operating ranges.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.34.1-34
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• 2001

We deal with robust control problem for singularly perturbed linear systems with norm-bounded structured uncertainty under state constraints. We assume that the norm-bounded uncertainty is composed of repeated scalar-block and full-block forms. In the structured uncertainty, repeated scalar block forms account for uncertain physical parameter value and full-block forms may be some unknown nonlinear dynamics. In order deal with uncertainty and state constraints, we use LMI(Linear Matrix Inequality). The original problem is decomposed into two well behaved reduced order problems. Shinc two LMI problems are completely independent, each solution can be computed simultaneously and work in parallel.

• Structural Engineering and Mechanics
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• v.74 no.3
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• pp.341-350
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• 2020

The present investigation is concerned with two dimensional deformation in a non local thermoelastic solid with two temperatures due to time harmonic sources. The nonlocal thermoelastic solid is homogeneous with the effect of two temperature parameters. Fourier transforms are used to solve the problem. The bounding surface is subjected to concentrated and distributed sources. The analytical expressions of displacement, stress components and conductive temperature are obtained in the transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerical simulated results are depicted graphically to show the effect of nonlocal parameter and frequency on the components of displacements, stresses and conductive temperature. Some special cases are also deduced from the present investigation.

• Macromolecular Research
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• v.15 no.3
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• pp.225-233
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• 2007

To improve the poor mechanical and low-temperature properties of glycidyl azide polymer (GAP)-based propellants, the addition of binders was investigated using GAP and flexible polymer backbone-structural polycaprolactone (PCP) at various weight(wt) ratios, and varying the ratio of Desmodur N-100 pluriisocyanate (N-100) to isophorone diisocyanate (IPDI). Using Gee's theory, the solubility parameter of the PCP network was determined, in order to elucidate the physical and chemical interaction between GAP and PCP. The structure of the binder networks was characterized by measuring the cross-link densities and molecular weights between cross-links ($M_c$) obtained by a swelling experiment using Flory-Rhener theory. The thermal and mechanical properties of the segmented block copolyurethane (GAP-b-PCP) binders prepared by the incorporation of PCP into the binder recipes were investigated, along with the effect of the different curatives ratios.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.34-39
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• 1989

The relationship between the solute retention and physical parameters describing the interaction between the solute and mobile phase was investigated to predict the solute retention easily in RPLC. The retention data of monosubstituted benzenes were measured on the $\mu$-Bondapak C18 and phenyl columns with methanol-water systems. The linear relationship between dielectric increment($\epdilon'$) and retention data was observed. When the solute form hydrogen bonding with solvent molecules, the slope of the ln k' vs. $\epdilon'$ plot is changed as the compositions is varied. The quadric relationship between mixed solvent solubility parameter ($\delta$M) and retention data was observed.

• Current Optics and Photonics
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• v.3 no.4
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• pp.275-284
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• 2019

Chirality is ubiquitous in physics and biology from microscopic to macroscopic phenomena, such as fermionic interactions and DNA duplication. In photonics, chirality has traditionally represented differentiated optical responses for right and left circular polarizations. This definition of optical chirality in the polarization domain includes handedness-dependent phase velocities or optical absorption inside chiral media, which enable polarimetry for measuring the material concentration and circular dichroism spectroscopy for sensing biological or chemical enantiomers. Recently, the emerging field of non-Hermitian photonics, which explores exotic phenomena in gain or loss media, has provided a new viewpoint on chirality in photonics that is not restricted to the traditional polarization domain but is extended to other physical quantities such as the orbital angular momentum, propagation direction, and system parameter space. Here, we introduce recent milestones in chiral light-matter interactions in non-Hermitian photonics and show an enhanced degree of design freedom in photonic devices for spin and orbital angular momenta, directionality, and asymmetric modal conversion.

• Geomechanics and Engineering
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• v.19 no.4
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• pp.295-305
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• 2019

The present paper is concerned with the investigation of disturbances in orthotropic thermoelastic medium by using fractional order heat conduction equation with three phase lags due to thermomechanical sources. Laplace and Fourier transform techniques are used to solve the problem. The expressions for displacement components, stress components and temperature change are derived in transformed domain and further in physical domain using numerical inversion techniques. The effect of fractional parameter based on its conductivity i.e., ($0<{\alpha}<1$ for weak, ${\alpha}=1$ for normal, $1<{\alpha}{\leq}2$ for strong conductivity) is depicted graphically on various components.