http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
양정엽,전병우 한국방송공학회 2010 방송과 미디어 Vol.15 No.4
복호화기 예측 부호화 기술은 종래의 예측 부호화 기술과 매우 다른 새로운 압축방식이다. 즉, 부호화기에서 모든 예측과정을 수행한 후, 복호화기가 예측부호화 오류로부터 원래의 데이터를 복원하는데 필요한 예측정보를 모두 전송하였던 기존 기술과는 달리, 이 예측정보를 복호화기 스스로 찾아내어 사용하는 방식이다. 이러한 이유로 압축 부호화 성능은 매우 향상 되었으나 반대로 복호화기는 예측치를 찾아내기 위하여 매우 많은 계산량을 소모하여야 한다는 단점도 있다. 본 고에서는 복호화기 예측 부호화기술의 다양한 방식과 이러한 문제점을 어떤 방식으로 개선하였는지 알아본다.
레이저 조사 방법으로 제조된 Co 나노닷의 초상자성 현상 관측
양정엽,윤갑수,도영호,구자현,김채옥,홍진표 한국자기학회 2004 한국자기학회 학술연구발표회 논문개요집 Vol.14 No.2
Superparamagnetic regions and magnetic anisotropic properties in randomly orientated Co nano dots (NDs) were investigated as a function of dot diameter, spacing, and density. The Co NDs were fabricated by intentionally exposing a laser source on ultra thin film. Various dot sizes are ultimately realized by changing laser power, scan condition, and initial film thickness. Magnetic hysteresis loops, angle-dependent magnetization, and temperature dependence magnetization of the Co NDs were measured with a superconducting quantum interference device. The analysis of magnetization and hysteresis loops was effectively used to determine superparamagnetic regions of the Co NDs. Up to now, the experimentally observed results repeal that room temperature superparamagnetic limit of our Co NDs was about 30 ㎚ in diameter, with the confirmation of high resolution transmission electron microscope.
양정엽,홍진표,김채옥,김주형,윤갑수,최원준,도영호 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.6
Metal-oxide-semiconductor (MOS) capacitors with metal nanoparticles (Co NP) were successfully fabricated by utilizing an external laser exposure technique for application of non-volatile memories. Images of high-resolution transmission electron microscopy reveal that the spherically shaped Co NP are clearly embedded in the gate oxide layer. Capacitance-voltage measurements exhibit typical charging and discharging effects with a large flat-band shift. The effects of the tunnel oxide thickness and the different tunnel materials are analyzed using capacitance-voltage and retention characteristics. In addition, the memory characteristics of the NP embedded in a high-permittivity material are investigated because the thickness of conventionally available SiO2 gates is approaching the quantum tunneling limit as devices are scaled down. Finally, the suitability of NP memory devices for nonvolatile memory applications is also discussed. The present results suggest that our unique laser exposure technique holds promise for the NP formation as floating gate elements in nonvolatile NP memories and that the quality of the tunnel oxide is very important for enhancing the retention properties of nonvolatile memory.
데이터 분할구조에서의 H.264/AVC 움직임 벡터의 다중표현 부호화와 다중표현 정합을 이용한 복호화
양정엽(Jungyoup Yang),전병우(Byeungwoo Jeon) 대한전자공학회 2007 電子工學會論文誌-SP (Signal processing) Vol.44 No.6
부호화된 동영상 데이터를 전송할 때 발생하는 전송 채널상의 에러로 손실된 정보는 수신측의 복호화 된 영상의 화질을 크게 열화 시킨다. 특히 움직임 벡터나 매크로 블록 모드 정보와 같이 중요도가 높은 정보가 손실될 경우, 에러로 인한 이러한 화질 저하는 더욱 심각하다. 이러한 문제를 해결하기 위한 에러 강인 기술의 하나로, 압축동영상 정보의 중요도에 따라 정보를 분할하여 중요도가 높은 정보를 더욱 강하게 보호할 수 있는 데이터 분할 기술이 제안되었다. 그러나 실제 채널 망의 경우 전송 데이터의 서로 다른 중요도를 지원할 수 있도록 하기 위해 일반적으로는 중요한 정보의 경우 동일 패킷을 여러 번 보내는 방식으로 UEP 효과를 얻도록 한다. 본 논문은 이러한 전송환경 하에 동일한 패킷을 중복 전송하는 종래의 기법에 비해 전송데이터 량을 감소시키면서도 전송 데이터 량 대비 화질을 증가시키기 위하여, H.264/AVC 표준의 데이터 분할 기술에 다중 표현 부호화 기술을 적용하여 데이터 분할 기술의 성능을 향상시키는 새로운 부호화와 복호화 방법을 제안한다. 제안된 방법은 데이터 분할된 H.264/AVC 표준의 움직임 벡터 정보를 효율적으로 다중 표현 부호화하고 독립적인 패킷으로 분할 전송함으로써 전송 에러에 의해 일부의 패킷을 손실하더라도 올바르게 전송된 패킷만으로 유사한 움직임 벡터 정보를 추정함으로써 에러은닉 기술의 성능을 향상시키고 채널 에러의 영향을 최소화시킨다. 또한 제안된 다중표현 정합 알고리즘을 사용하여 움직임 벡터의 추정정확도를 향상시켜 복원영상의 화질을 개선한다. When compressed video data is transmitted over error-prone network such as wireless channel, data is likely to be lost, so the quality of reconstructed picture is severely decreased. It is specially so in case that important information such as motion vector or macroblock mode is lost. H.264/AVC standard includes DP as error resilient technique for protecting important information from error in which data is labeled according to its relative importance. But DP technique requires a network that supports different reliabilities of transmitted data. In general, the benefits of UEP is sought by sending multiple times of same packets corresponding to important information. In this paper, we propose MDC technique based on data partitioning technique. The proposed method encodes motion vector of H.264/AVC standard into multiple parts using MDC and transmits each part as independent packet. Even if partial packet is lost, the proposed scheme can decode the compressed bitstream by using estimated motion vector with partial packets correctly transmitted, so that achieving improved performance of error concealment with minimal effect of channel error. Also in decoding process, the proposed multiple description matching increases the accuracy of estimated lost motion vector and quality of reconstructed video.
Investigation of Cu2ZnSnS4 solar cell buffer layer fabricated via spray pyrolysis
이동호,양정엽 한국물리학회 2021 Current Applied Physics Vol.21 No.-
Copper zinc tin sulfide solar cells were fabricated by using spray pyrolysis from a window layer to an absorber layer. ZnS and In2S3 buffer layers were deposited on the TiO2 layer, and the photovoltaic characteristics were investigated. The ZnS buffer demonstrated a poor photovoltaic performance because of its poor surface coverage and micro-cracks at fluorine-doped tin oxide/TiO2 layers. The In2S3 buffer layer sprayed at low temperature (<360 ◦C) showed a large difference between photo and dark currents beyond the open-circuit voltage (VOC). When the spraying temperature exceeded 390 ◦C, the devices showed high dark leakage currents at reverse biases because of the high conductivity of the buffer layer, resulting in decreased VOC and short-circuit current density (JSC). The optimum temperature for spraying In2S3 is 360 ◦C, and the best performing device showed 410 mV, 30.4 mA/cm2, 35.3%, and 4.4% of VOC, JSC, fill factor, and efficiency, respectively.
in - situ 열처리기법을 통한 자기터널접합의 열적 안정성에 관한 연구
윤갑수,구자현,양정엽,도영호,김기웅,김채옥,홍진표 한국자기학회 2004 한국자기학회 학술연구발표회 논문개요집 Vol.14 No.2
A new IDRA process was performed to enhance thermal stability of MTJs. After the IDRA process, high TMR radtio of 55 % was obtained at the annealing temperature of 350 ?. The increased TMR ratio of MTJs after IRDA process could be explained by both the enhancement of average barrier height and the reduction of barrier height. Finally, the SPRS results agreed with those of MTJs that were pre-treated by the IDRA process.
Kim, C. O.,Yoon, K. S.,Yang, J. Y.,Kim, Y. D.,Hong, J. P. 漢陽大學校 自然科學硏究所 2003 自然科學論文集 Vol.23 No.-
We clearly observe localized antiferromagnetic phases at interfaces between AIOx in-sulating barriers and CoFe bottom electrodes in-duced by the over-diffusion of oxygen atoms into the bottom electrode.
Dependence of the Oxidation Geometry on Insulating AlOx Barriers in Ferromagnetic Tunnel Junctions
ChaeOkKim,KapSooYoon,양정엽,JaeHyunPark,김은규,JinPyoHong 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.41 No.1
A rf reactive oxidation method with an o-axis geometry structure has been used to enhance the electrical and the structural properties of the AlOx barriers in magnetic tunnel junction (MTJ) devices. This o-axis oxidation geometry is intentionally designed to indirectly expose to a barrier mixed plasma of oxygen and argon. Experimental observation indicates a decrease in the average aspect ratio of the grains from 0.6 to 0.3. This reduction likely originated from a reduction of the strong ion bombardment eect on the barrier. The electrical breakdown voltage and magnetoresistance of the MTJ increased from 0.4 V to 1.2 V and from 5 % to 16 %, respectively, when compared with the MTJ devices oxidized using a conventional rf reactive oxidation technique with an on-axis geometry. .