• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.4
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• pp.321-332
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• 2017

In order to build a general model of a high-throughput uranium electrorefining process according to the electrode configuration, numerical analysis was conducted using the COMSOL Multiphysics V5.3 electrodeposition module with Ordinary Differential Equation (ODE) interfaces. The generated model was validated by comparing a current density-potential curve according to the distance between the anode and cathode and the electrode array, using a lab-scale (1kg U/day) multi-electrode electrorefiner made by the Korea Atomic Energy Research Institute (KAERI). The operating temperature was $500^{\circ}C$ and LiCl-KCl eutectic with 3.5wt% $UCl_3$ was used for molten salt. The efficiency of the uranium electrorefining apparatus was improved by lowering the cell potential as the distance between the electrodes decreased and the anode/cathode area ratio increased. This approach will be useful for constructing database for safety design of high throughput spent nuclear fuel electrorefiners.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.11
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• pp.24-32
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• 2002

In this paper we implemented various image processing filtering using the format converter. This design method is based on realized the large processor-per-pixel array by integrated circuit technology. These two types of integrated structure are can be classify associative parallel processor and parallel process DRAM(or SRAM) cell. Layout pitch of one-bit-wide logic is identical memory cell pitch to array high density PEs in integrate structure. This format converter design has control path implementation efficiently, and can be utilize the high technology without complicated controller hardware. Sequence of array instruction are generated by host computer before process start, and instructions are saved on unit controller. Host computer is executed the pixel-parallel operation starting at saved instructions after processing start. As a result, we obtained three result that 1)simple smoothing suppresses higher spatial frequencies, reducing noise but also blurring edges, 2) a smoothing and segmentation process reduces noise while preserving sharp edges, and 3) median filtering, like smoothing and segmentation, may be applied to reduce image noise. Median filtering eliminates spikes while maintaining sharp edges and preserving monotonic variations in pixel values.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.4
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• pp.155-159
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• 2008

In this work, we report synthesis of free-standing ZnO/Zn core-shell micro-polyhedrons using metal Zn pellets as a source material by the thermal chemical vapor deposition process. Scanning and transmission electron microscopy measurements were introduced to investigate morphologies and structural properties of as-grown ZnO/Zn core-shell micro-polyhedrons. It was found that micro-polyhedrons were composed of inner single-crystalline metal Zn surrounded by single-crystalline ZnO nanorod arrays. The inner single crystalline metal Zn with micro-scale diameter has a hexagonal crystal structure. Diameter and height of ZnO nanorods covering the metal Zn surface are below 10 nm and 100 nm, respectively. It was also confirmed that c-axis oriented ZnO nanorods are single crystalline with a hexagonal crystal structure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.1
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• pp.111-118
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• 2005

The shape of vertical pattern of base station antenna affects greatly quality of the communication of not only a service zone but also adjacent cells and then it is an important point to be considered in designing cell coverage. Currently type of vertical patterns to be applied to base station antenna are divided into five classes. In designing antenna, these five classes are applied solely or compositely according to the environment to be used antenna. In this paper, the dual polarized antenna for base station that is with a continuous electrical down tilting and with a shaped beam pattern, that an upper side lobe is suppressed and a lower null is filled, is designed and fabricated for synthesizing of the shape beant the pattern synthesis methods proposed by R. S. Elliott is used sequentially and for the electrical don tilting, the phased array theory is applied. Measured results show the down tilting range from 0° to 14°, the gain of Min. 13.3dBi and the upper side lobe of Max. -23dB. And we verified that upper side lobe is not to vary greatly and null filling performance is favorable overall.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.510-520
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• 2011

In this paper, we propose a new multiplication algorithm for primitive polynomial with all 1 of coefficient in case that m is odd and even on finite fields $GF(3^m)$, and compose the multiplier with parallel input-output module structure using the presented multiplication algorithm. The proposed multiplier is designed $(m+1)^2$ same basic cells that have a mod(3) addition gate and a mod(3) multiplication gate. Since the basic cells have no a latch circuit, the multiplicative circuit is very simple and is short the delay time $T_A+T_X$ per cell unit. The proposed multiplier is easy to extend the circuit with large m having regularity and modularity by cell array, and is suitable to the implementation of VLSI circuit.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.10-22
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• 2015

Recently, 3rd Generation Partnership Project (3GPP) has developed sidehaul system to cope with the explosively increasing mobile data traffic. The sidehaul system is based on single carrier-frequency division multiple access (SC-FMDA) due to its low peak to average power ratio (PAPR). Also, antenna array is designed to support multiple input multiple output (MIMO) in a restricted space. In this paper, we design the antenna array about uniform linear array (ULA), uniform circular array (UCA) and uniform planar array (UPA), and analysis the performance in sidehaul system. In addition, we propose the novel hybrid receiver full suppression cancellation (FSC) to reduce the interference from neighbor cell in sidehaul system. The proposed receiver can suppress and cancel the interference by combining interference rejection combining (IRC) with successive interference cancellation (SIC).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10A
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• pp.952-959
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• 2006

In this paper, 2-D RAKE receiver simulator is made which beamforming technique is applied to in WCI)MA uplink basestation, and the performance is compared with that of 1-D RAKE receiver with varying the number of array elements, RAKE fingers and users. To model angular component of received signal and interfering signals due to multiple access, it is assumed that multiple users are located in the arbitrary direction of the same distance far from the basestation within a sector of the cell, and the channel simulator is made by using Geometry Based Single Bounce Elliptical Model(GBSBEM) suggested by Rappaport. BER performance is compared and analyzed with the various choise of the number of array elements, the number of RAKE fingers, the number of users and Eb/No. These results indicate that increasing the number of array elements eliminates efficiently multiple access interfering signals and improves dramatically BER performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1C
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• pp.72-80
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• 2003

This paper proposed the method of finding optimal weight vectors for enhancing the performance of an adaptive array antenna system by adopting a novel beam-forming algorithm in CDMA (code division multiple access) channel. This algorithm is a liberalized power method, based on power method, with the total computational load, O(4N). Where, N denotes the number of antenna elements. The performance of the proposed algorithm is shown in terms of SER (symbol error rates), allowable capacity, and the convergence characteristic in IS2000 1X CDMA channel. As a result of simulations, the adaptive way antenna system allows 6-10 times more users than the conventional one in a cell of a base station. Furthermore, the proposed algorithm shows superior performance to the conventional one regarding symbol error rates, converging characteristics, and computational load.

• Korean Journal of Optics and Photonics
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• v.31 no.3
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• pp.148-154
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• 2020

In this paper we propose a plasmonic color filter with a novel nanopattern. The suggested pattern, called a "polyperiodic hole array" (PPHA), is introduced to solve the angle dependence of the optical response that originates from the periodic structure. We set the diameter and period of the hole to make a green color filter, and set the unit-cell size and metal and dielectric thicknesses in consideration of the propagation length and skin depth. The periodic hole arrays are locally rotated to make a PPHA pattern, resulting in a globally aperiodic yet partially periodic pattern. As a result, compared to a general pattern, the PPHA nanostructured color filter has a maximum 40% improvement in spectral shift when the angle of incidence is increased from 0° to 30°. Transmittance reduction was also alleviated by 30%. This work will improve the performance of nanostructured color filters and help with nanotechnology being applied industrially to imaging devices, including displays and image sensors.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.232-237
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• 2024

In this paper, a broadband double dipole quasi-Yagi antenna using a 4×2 meander line array structure for maintaining 8 dBi gain was studied. The 4×2 meanderline array structure consists of a unit cell in the shape of a meanderline conductor, and it was placed above the second dipole antenna of the double dipole quasi-Yagi antenna. A double dipole quasi-Yagi antenna with generally used multiple strip directors was designed on an FR4 substrate with the same size, and the input reflection coefficient and gain characteristics were compared. Comparison results showed that the impedance frequency bandwidth increased by 6.3% compared to when using the multiple strip directors, the frequency bandwidth with a gain of 8 dBi or more increased by 10.1%, and average gain also slightly increased. The frequency band of the fabricated antenna for a voltage standing wave ratio less than 2 was 1.548-2.846 GHz(59.1%), and gain was measured to be more than 8 dBi in the 1.6-2.8 GHz band.