• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.2
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• pp.33-38
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• 2004

We have demonstrated a tunable Inter based on an asymmetric directional coupler made of a side-polished polarization maintaining fiber coupled with a polymer planar waveguide. The thermo-optic effects of the polymer planar waveguide induced by a micro-strip heater placed on the top layer of the device leads to shift of resonance wavelength of the coupler. The fabricated device exhibited wide tunable range exceeding 230 nm with 720 ㎽ of applied electrical power.

• Fibers and Polymers
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• v.3 no.1
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• pp.43-48
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• 2002

A series of monoazo disperse dyes based on 2-amino-4-phenylthiazole was prepared using various N,N-dialkvlaniline derivatives as the coupling component. The dyes were characterized by IR spectral studies, visible absorption spectroscopy and elemental analysis. The dyeing performance of these dyes was assessed on cellulose triacetate and nylon fibers. These dyes were found to give a wide range of colour shades varying from bright red to royal blue with very good depth, brightness and levelness on fibers. The dyed fibers showed good to very good light fastness and very good to excellent fastness to washing, perspiration, rubbing and sublimation. The dyebath exhaustion and fixation on the fibers were found to be very good.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.37-38
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• 2017

본 논문에서는 승압형 PFC 컨버터를 사용하고 풀브리지-하프브리지 제어를 적용한 넓은 결합계수 범위에서 동작하는 2-stage 자기유도방식 무선전력전송 시스템의 설계 방법을 제안한다. 결합계수, 출력전압 범위 및 bridgeless 정류기의 최대 승압비를 고려하여 풀브리지-하프브리지 동작 영역과 승압형 PFC 컨버터의 DC link 전압 범위를 설계한다. 설계 결과를 기존 시스템과 비교하고 시뮬레이션을 통하여 이를 검증한다.

• Journal of the Korean Society of Combustion
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• v.15 no.4
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• pp.22-28
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• 2010

The Direct Quadrature Method of Moments (DQMOM) has been presented for the solution of population balance equation in the wide range of the multi-phase flows. This method has the inherently interesting features which can be easily applied to the multi-inner variable equation. In addition, DQMOM is capable of easily coupling the gas phase with the discrete phases while it requires the relatively low computational cost. Soot inception, subsequent aggregation, surface growth and oxidation are described through a population balance model solved with the DQMOM for soot formation. This approach is also able to represent the evolution of the soot particle size distribution. The turbulence-chemistry interaction is represented by the laminar flamelet model together with the presumed PDF approach and the spherical harmonic P-1 approximation is adopted to account for the radiative heat transfer.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.92-98
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• 1996

parallel bonding wires separaated with a screeing bonding wire are proposed and characterized in order to redue mutual coupling and parasitics of high-speed and high-density device packaging. The mehtod of moments (MoM) with the incorporation of the ohmic loss has been used in a wide range of frequencies. From the calculated results, we have found that the screening bonding wire effectively reduces inductive and capacitive crostalk levels more than 3dB. the parasitic self inductance is also reduced more than 12% by the screening effect. Therefore, for a general VLSi package, the packaging density can be increased more than 30% using the screening bonding wire. This screeing bonding wire and the analysis can be effectively used to reduce crosstalk and increase packaging density of high density devices.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1376-1378
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• 1999

Most conventional protection relays are based on processing information in the spectrum that is close to or at power frequency. It is, however, widely known that faults on transmission lines produce frequency components of a wide range In this respect, this paper describes the basis of a Protection technique for transmission lines which utilises high-frequency components. Fault-generated signals caused by post-fault and the signal derived from stack tuner is connected to the coupling capacitor of CVT. Digital signal processing is then applied to the captured information to determine whether the fault is inside or outside the Protected zone, and to discriminate the fault type on transmission line.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.2
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• pp.208-219
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• 1999

Springs have been employed in a wide range of mechanical systems. This work deals with the concept of an adaptable spring mechanism which can arbitrarily modulate its spring characteristics. The adaptable spring is desired for enhancing performances of various mechanical systems employing springs. We demonstrate that such adaptable springs can be realized by adapting anthropomorphic musculoskeletal structures of the human upper-extremity, which possesses highly nonlinear kinematic-coupling among redundant muscles existing in its structures. This phenomenon has been explained by several human arm models. Based on the analysis results, we propose multi-degree-of-freedom spring mechanisms resembling the musculoskeletal structure of the human upper-extremity, and verifiy the applicability of these mechanisms through simulation.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.1
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• pp.101-107
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• 1988

This paper proposes a circuit extractor which extracts a netlist from the CIF input file cntaining the layout mask artwork informations. The circuit extractor extracts transistors and their interconnections, and calculates circuit parameter such as parasitic resistance and parasitic capacitance from the mask informations. When calculating the parasitic resistance, we consider the current flow path to reduce the errors caused by the resistance approximation. Similarly, we consider the coupling capacitance which has an effect on the circuit characteristics, when the parasitic capacitances are calculated. Therefore, using these parameter values as an input to circuit simulation, the circuit characteristics such as delay time can be estimated accurately. The presented circuit extraction algorithm uses a multiple storage quad tree as a data sturucture for storing and searching the 2-dimensional geometric data of mask artwork. Also, the proposed algorithm is technologically independent to work across a wide range of MOS technologies without any change in the algorihm.

• Current Optics and Photonics
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• v.1 no.3
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• pp.214-220
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• 2017

A wavelength filter based on a polymer Bragg reflector has received much attention due to its simple structure and wide tuning range. Tilted Bragg gratings and asymmetric Y-branches are integrated to extract the reflected optical signals in different directions. To optimize device performance, design procedures are thoroughly considered and various design parameters are applied to fabricated devices. An asymmetric Y-branch with an angle of $0.3^{\circ}$ produced crosstalk less than -25 dB, and the even-odd mode coupling was optimized for a grating tilt angle of $2.5^{\circ}$, which closely followed the design results. Through this experiment, it was confirmed that this device has a large manufacturing tolerance, which is important for mass production of this optical device.

• 한국전산유체공학회:학술대회논문집
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• 1997.10a
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• pp.143-148
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• 1997

Differential pressure Venturi cone flowmeter is an advanced flowmeter which has many advantages such as wide range of measurement, high accuracy, excellent flow turndown ratio, low headless, and short installation pipe length requirement, etc. Like other differential pressure flowmeter, Venturi cone flowmeter uses the law of energy conservation, but its shape and position make it perform better than others. The cone acts as its own flow conditioner and mixer, fully conditioning and mixing the flow prior to measurement. For the analysis, we use Reynolds-averaged Navier-Stokes equations and $k-{\omega}$ turbulence model. The equations are fully trans-formed in the computational coordinates, the pressure-velocity coupling is made through SIMPLER algorithm, and the equations are discretized using analytic solutions of the linearized equations(Finite Analytic Method). At the end of the paper, using the result of analysis, We propose a new shape of cone with the hope of drag reduction and high performance.