• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.161-164
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• 2013

본 논문에서는 다양한 멀티미디어 코덱을 고속으로 처리하기 위하여 전용하드웨어가 아닌 병렬 어레이 프로세서 기반의 U-Chip(Universal-Chip) 구조를 제안하고 TSMC 80nm 공정을 사용하여 11,865,090개의 게이트 수를 가지는 칩으로 개발하였다. U-Chip은 역양자화(IQ), 역변환(IT), 움직임 보상(MC) 연산을 위한 $4{\times}16$ 개의 프로세싱 유닛으로 구성된 병렬 어레이 프로세서와 문맥적응적 가변길이디코딩(CAVLC)을 위한 비트스트림 프로세서와 인트라 예측(IP), 디블록킹필터(DF) 연산을 위한 순차 프로세서와 DMAC의 데이터 전송 및 각 프로세서를 제어하여 병렬 파이프라인 스케쥴링을 처리하는 시퀀서 프로세서 등으로 구성된다. 1개의 프로세싱 유닛에 1개의 매크로블록 데이터를 맵핑하여 총 64개의 매크로블록을 병렬처리 하였다. 64개 매크로블록의 대용량 데이터 전송 시간과 각 프로세서들의 연산을 동시에 병렬 파이프라인 함으로서 전체 연산 성능을 높일 수 있는 이점이 있다. 병렬 파이프라인 구조의 H.264 디코더 프로그램을 개발하였고 제작된 U-Chip을 통해 $720{\times}480$ 크기의 베이스라인 프로파일 영상에 대하여 코어 192MHz 동작, DDR 메모리 96MHz 동작에서 30fps의 처리율을 가짐을 확인하였다.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.490-495
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• 2003

In steel-making process of iron and steel industry, the purity and quality of steel can be dependent on the amount of CO contained in the molten metal. Recently, the supersonic oxygen jet is being applied to the molten metal in the electric furnace and thus reduces the CO amount through the chemical reactions between the oxygen jet and molten metal, leading to a better quality of steel. In this application, the supersonic oxygen jet is limited in the distance over which the supersonic velocity is maintained. In order to get longer supersonic jet propagation into the molten metal, a supersonic coherent jet is suggested as one of the alternatives which are applicable to the electric furnace system. It has a flame around the conventional supersonic jet and thus the entrainment effect of the surrounding gas into the supersonic jet is reduced, leading to a longer propagation of the supersonic jet. In this regard, gasdynamics mechanism about why the combustion phenomenon surrounding the supersonic jet causes the jet core length to be longer is not yet clarified. The present study investigates the major characteristics of the supersonic coherent jet, compared with the conventional supersonic jet. A computational study is carried out to solve the compressible, axisymmetric Navier-Stokes equations. The computational results of the supersonic coherent jet are compared with the conventional supersonic jets.

• Journal of the Institute of Convergence Signal Processing
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• v.1 no.1
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• pp.89-96
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• 2000

In this paper, we propose a vision algorithm for the inspection of very small RF-chip inductor which is used in mobile-communication terminal. The proposed method divides coil part from the inductor body by local adaptive thresholding and integral projection method. After dividing work, the coil components are extracted by thinning and labelling techniques. The test items are the number of turns, the intervals in coil, and the measure of uniformity between the extracted lines. If the values of these are more than the specific value a tested product is decided bad one. In the simulation, the proposed method has a good performance.

• Korean Journal of Optics and Photonics
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• v.22 no.1
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• pp.40-45
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• 2011

Design and fabrication of a TCRR (Triple-coupler Ring Resonator) filter which can provide a doubled FSR (Free Spectral Range) compared with a conventional DCRR (Double-coupler Ring Resonator) filter, are discussed. Through the use of a polymer material with a good thermo-optic property and with high contrast between core and cladding polymer, a compact TCRR filter composed of straight and curved buried waveguides of small radius is designed and fabricated. The transmission characteristics from the through and drop ports are measured using a tunable laser and a fiber array block, and the FSR is observed to be 4.4 nm, about twice that of DCRR filter, and almost the same as that obtained from the analysis using a transfer matrix method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.803-810
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• 2017

the liquid oxygen transitions to a supercritical state, causing rapid changes in properties and pseudo boiling in supercritical combustion. the combustion reaction operating in a supercritical state depends on the turbulence diffusion caused by difference of density, therefore, a study of the diffusion flow and pseudo boiling is required. Many researchers have studied these phenomena in the supercritical combustion, but A case study by various variables is inadequate. In this study, the flow field and flame structure were investigated numerically by changing the recirculation flow and liquid oxygen core length through oxygen-fuel ratio(O/F), combustor diameter and recess ratio at supercritical pressure condition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2154-2162
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• 2009

This paper describes a scalar multiplier for Elliptic curve cryptography for smart card security. The scaler multiplier has 163-bits key size which supports the specifications of smart card standard. To reduce the computational complexity of scala multiplication on finite field, the non-adjacent format (NAF) conversion algorithm which is based on complementary recoding is adopted. The scalar multiplier core synthesized with a 0.35-${\mu}m$ CMOS cell library has 32,768 gates and can operate up to 150-MHz@3.3-V. It can be used in hardware design of Elliptic curve cryptography processor for smartcard security.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.296-297
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• 2007

PMN-PZT 단층 및 다층 후막을 알루미나 기판위에 켄티레버 형태로 제작하여, 외부의 미소 진동에 의한 마이크로 발전 특성을 고찰하였다. 미소 변위에 의한 마이크로 발전 특성은 켄티레버의 무게(load), 진동수, 켄티레버의 길이 등에 밀접한 영향을 미치므로 이에 준한 요소를 고려하여 여러 가지 변수로 실험하였다. 연구 결과 서로 다른 소재의 기판과 발전체의 계면 분리 현상, 전극과 발전체의 분리 현상, 소결 온도 등이 소재 측면의 문제점으로 크게 대두되었으며, $5{\times}20mm$ 기판위에 형성된 발전체의 특성은 $1.1k{\Omega}{\sim}1M{\Omega}$의 부하에 따른 전압변동이 0.01V에서 3.6V로 큰 차이가 났다. 켄티레버의 로드의 변화에 대한 피크 전압은 $1.9{\sim}{\pm}2.8V$로 조사되었으며, 출력은 $0.45{\sim}4{\mu}W$로 측정되었다. 그러나 이런 외부 조건 보다 압전체의 공진 특성과 진동수는 가장 중요한 요인으로 나타났으며, 몇몇 문제가 해결될 경우 마이크로 발전소자로의 활용 가능성이 있는 것으로 조사되었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.686-689
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• 2009

This paper describes a scalar multiplier for Elliptic curve cryptography. The scalar multiplier has 163-bits key size which supports the specifications of smart card standard. To reduce the computational complexity of scalar multiplication on finite field $GF(2^{163})$, the Non-Adjacent-Format (NAF) conversion algorithm based on complementary recoding is adopted. The scalar multiplier core synthesized with a $0.35-{\mu}m$ CMOS cell library has 32,768 gates and can operate up to 150-MHz@3.3-V. It can be used in hardware design of Elliptic curve cryptography processor for smart card security.

• Annual Conference on Human and Language Technology
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• 2019.10a
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• pp.97-102
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• 2019

KorQuAD 2.0은 총 100,000+ 쌍으로 구성된 한국어 질의응답 데이터셋이다. 기존 질의응답 표준 데이터인 KorQuAD 1.0과의 차이점은 크게 세가지가 있는데 첫 번째는 주어지는 지문이 한두 문단이 아닌 위키백과 한 페이지 전체라는 점이다. 두 번째로 지문에 표와 리스트도 포함되어 있기 때문에 HTML tag로 구조화된 문서에 대한 이해가 필요하다. 마지막으로 답변이 단어 혹은 구의 단위뿐 아니라 문단, 표, 리스트 전체를 포괄하는 긴 영역이 될 수 있다. Baseline 모델로 구글이 오픈소스로 공개한 BERT Multilingual을 활용하여 실험한 결과 F1 스코어 46.0%의 성능을 확인하였다. 이는 사람의 F1 점수 85.7%에 비해 매우 낮은 점수로, 본 데이터가 도전적인 과제임을 알 수 있다. 본 데이터의 공개를 통해 평문에 국한되어 있던 질의응답의 대상을 다양한 길이와 형식을 가진 real world task로 확장하고자 한다.

• Journal of the Korean Wood Science and Technology
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• v.49 no.2
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• pp.107-121
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• 2021

The purpose of this study is to optimize the bonding method of the plywood suitable for cross-laminated timber (CLT) with plywood as a core by analyzing the flexural performance and failure mode according to the lamina species, the method of bonding plywood in the longitudinal direction, and whether or not adhesive is applied to the joint. In the case of the Douglas fir lamina layer, the modulus of elasticity decreased by about 11.5% due to longitudinal bonding, and the modulus of rupture increased or decreased according to the adhesive application and bonding method. The optimal conditions were derived as the butt joint without adhesive, half lap joint with adhesive, and butt joint. In the case of the larch lamina layer, the modulus of rupture and the modulus of elasticity decreased by about 15% and 40%, respectively. When using the half lab joint and tongue & groove joint, it is believed that it reduces the load transmitted to the middle layer by primarily preventing the failure on flexure at the joint of the plywood layer. From the results of this study, the larch lamina layer used in the manufacturing process of Ply-lam CLT did not show any difference based on the bonding method. Butt joint and half lap joint bonding method are determined to be suitable when using Douglas fir lamina layer.