Hyeong-Seok Kim

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In this paper, a new energy harvesting technology using stray electric field of an electric power line is presented. It is found that energy can be harvested and stored in the storage capacitor that is connected to a cylindrical aluminum foil wrapped around a commercial insulated 220 V power line. The average current flowing into 47 μF storage capacitor is(More)
In this paper, a fuzzy c-means clustering algorithm is proposed to determine the optimum deployment of sensor nodes. It is for a given application space to improve energy efficiency and reduce cost. We performed simulation for ¡®L' shaped area to find minimum number and optimum location of sensor nodes.
A micro- and nanoscale complex structure made of a high refractive index polymer (n = 2.08) was formed on the ITO electrode layer of an edge-emitting type GaN blue light-emitting diode (LED), in order to improve the photon extraction efficiency by suppressing total internal reflection of photons. The nanoimprint lithography process was used to form the(More)
An on-package dual-mode square-loop band pass filter is studied by applying a non-uniform finite difference time domain (NUFDTD) method. The filter is integrated on a package containing a transceiver, and it is designed to operate in dual-modes, i.e., TM100 and TM010, to ensure a good electric performance around the center frequency at 5.25 GHz, which is(More)
This paper shows an improved particle swarm optimization (PSO) to design a novel compact ultra wideband (UWB) filter. The filter consists of an only one-cell composite right and left handed-transmission line (CRLH-TL) resonator, stepped impedance (SI), and two spurlines. The one-cell CRLH-TL resonator has a compact size and forms a wide passband. An SI and(More)
Carbon based spin-on organic hardmask (C-SOH) was used as an imprint resin to fabricate sub 50 nm sized patterns. Imprinting of C-SOH was done with a polyurethaneacrylate (PUA) stamp. Patternability and etch resistance of the C-SOH resin was compared to poly(methyl methacrylate) (PMMA). C-SOH can be patterned at the nanosize using imprint lithography and(More)
This paper proposes a hybrid algorithm based on Genetic Algorithm (GA) and Evolution Strategy (ES). The GA is not successful in searching an optimal solution in the view point of convergence speed and solution quality. The ES has the risk of being trapped in a local minimum. The hybrid algorithm is composed of GA and ES in order to make up for these defects(More)
This paper presents how to determine the thickness of hysteresis ring of hysteresis motor using the finite element method combined with a vector hysteresis model. From the magnitude and direction of the magnetic field intensity, the magnetization of each ring element is calculated by the vector hysteresis model and the torque can be obtained from the vector(More)