Avidin Induced Silver Aggregation for SERS-based Bioassay

Youngjo Sa,Lei Chen,정영미 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

We developed a simple and effective method for the SERS-based detection of protein-small molecule complexes and label-free proteins using avidin-induced silver aggregation. Upon excitation with light of the appropriate wavelength (633 and 532 nm), the aggregated silver nanoparticles generate a strong electric field that couples with the resonance of the molecules (atto610 and cytochrome c), increasing the characteristic signals of these molecules and resulting in sensitive detection. The detection limit of biotin with the proposed method is as low as 48 ng/mL. The most important aspect of this method is the induction of silver aggregation by a protein (avidin), which makes the silver more biocompatible. This technique is very useful for the detection of protein-small molecule complexes.

Hierarchical Likelihood and Statistical Inferences

Youngjo Lee,Il Do Ha 계명대학교 자연과학연구소 2013 Quantitative Bio-Science Vol.32 No.2

In this paper we review the two existing ways, Bayesian and Fisher approaches, for statistical inferences. Then we discuss the hierarchical likelihood (h-likelihood; Lee and Nelder, 1996) framework, including its necessity and advantages. The usefulness of h-likelihood is illustrated via an example for prediction problem and analyses of two wellknown real data sets.

zFTL: power-efficient data compression support for NAND flash-based consumer electronics devices

Youngjo Park,Jin-Soo Kim IEEE 2011 IEEE transactions on consumer electronics Vol.57 No.3

<P>Flash translation layers play an important role in determining the storage performance and lifetime of NAND flash-based consumer electronics devices. In this paper, we present a flash translation layer called zFTL, which reduces the amount of data written to NAND flash memory by supporting on-line, transparent data compression based on the X-Match algorithm. To minimize compression overhead and power consumption, we also propose a novel prediction scheme that identifies incompressible data in advance without going through full compression. Our evaluations with five real-world workloads show that zFTL successfully enhances storage performance and lifetime by improving the write amplification factor (WAF) by a factor of 2.6 (geometric mean) compared to the case without compression support. In addition, we find that the proposed prediction scheme is effective in reducing power consumption by skipping compression for incompressible data.</P>

Communication protocol design for individual control of System air conditioner wired remote controller

YoungJo Jang,DongSeog Han 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

Wired remote control of system air conditioner is connected to the indoor unit product to synchronize the functions between the indoor unit and the wired remote controller through mutual communication to determine the communication speed and communication method. Accordingly, as the development of product functions has progressed, the communication protocol of the wired remote control has been expanded, and continuous management has been required to secure the compatibility between the existing protocol and the additional protocol, and synchronization time has been increased. In addition, due to the communication structure of the wired remote control, one individual control is possible, and when two or more products are connected, it is judged as a group control state to perform the same operation based on the same function. With the wired remote control replacing the display of the indoor unit product, customer demand from the interior perspective is increasing, and the need to control various indoor units in one product is increasing. The communication structure that can individually control the indoor unit was designed and the communication speed was also changed to improve the synchronization time and reaction time compared to the existing products. As a result, at the current level, two indoor units have been individually made, and a communication structure capable of individually controlling more indoor units has been implemented.

Characterization of ZnO nanorod arrays fabricated on Si wafers using a low-temperature synthesis method

Tak, Youngjo,Park, Dongseok,Yong, Kijung American Vacuum Society 2006 JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B - Vol.24 No.4

Fabrication of ZnO/CdS core/shell nanowire arrays for efficient solar energy conversion

Tak, Youngjo,Hong, Suk Joon,Lee, Jae Sung,Yong, Kijung Royal Society of Chemistry 2009 Journal of materials chemistry Vol.19 No.33

<P>ZnO/CdS core/shell nanowire heterostructure arrays are fabricated by a two-step chemical solution method for use in semiconductor-sensitized photoelectrochemical cells (PECs). The successive ion layer adsorption and reaction (SILAR) shows a remarkable controllability of CdS shell thickness, which affects visible-light absorption properties and PEC performances of the heterostructures. The cell has a high short-circuit photocurrent density of 7.23 mA/cm<SUP>2</SUP> with a power conversion efficiency of 3.53% under AM 1.5G illumination at 100 mW/cm<SUP>2</SUP>. These results demonstrate that the ZnO/CdS core/shell heterostructure nanowire arrays can provide a facile and compatible frame for the potential applications in nanowire-based solar cells.</P> <P>Graphic Abstract</P><P>ZnO/CdS core/shell nanowires arrays show enhanced photoelectrochemical properties due to increased visible-light absorption capability and charge separation ability compared to bare ZnO nanowire arrays. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b904993b'> </P>

A Fast Intra Prediction Method Using the Distribution of Adjacent Pixels in HEVC

KIM, Youngjo,BYUN, Juwon,KIM, Jaeseok 'Institute of Electronics, Information and Communi 2014 IEICE transactions on fundamentals of electronics, Vol.ea97 No.1

쿼드트리 구조와 SATD를 이용한 HEVC 인코더의 고속 인트라 예측 방식

김영조(Youngjo Kim),김재석(Jaeseok Kim) 대한전자공학회 2014 전자공학회논문지 Vol.51 No.3

본 논문은 HEVC(high efficiency video coding) 인코더의 인코딩 시간을 줄이기 위한 고속 인트라 예측 방식을 제안한다. 제안하는 고속 인트라 예측 방식은 쿼드트리 구조와 SATD(Sum of Absolute Transformed Differences)를 사용한다. HEVC는 8×8 이상의 블록에서 SATD 값을 구하기 위해 8×8 hadamard 변환을 이용한 8×8 SATD 값을 사용한다. 제안하는 방식은 16×16 이상의 블록에서 각각의 8×8 SATD 결과를 이용해서 최적 SATD 값을 산출한다. 그 후, RDO를 위한 후보 모드의 SATD와 산출된 최적 SATD의 비교를 기반으로 후보 모드를 제거한다. 후보 모드를 제거함으로써 제안하는 방식은 RDO의 연산을 줄이고 전체 인코딩 시간을 줄이게 된다. 제안하는 방식은 8×8 블록에서는 추가로 4×4 SATD를 사용하여 최적 SATD를 구한다. 실험 결과 제안하는 방식은 거의 압축 성능 손실 없이 HM 12.1에 비해 5.33%의 인코딩 시간 감소 효과를 얻을 수 있었다. This paper proposes a fast intra prediction method to reduce encoding time for the HEVC(high-efficiency video coding) encoder. The proposed fast Intra prediction method uses quadtree structure and SATD(Sum of Absolute Transformed Differences). In HEVC, a 8×8 SATD value using 8×8 hadamard transform is used to calculate a SATD value for 8×8 or larger blocks. The proposed method calculates the best SATD value by using each 8×8 SATD result in 16×16 or larger blocks. After that, the proposed method removes a candidate mode for RDO(Rate-Distortion Optimization) based on comparing SATD of the candidate mode and the best SATD. By removing candidate modes, the proposed method reduces the operation of RDO and reduces total encoding time. In 8×8 block, the proposed method uses additional 4×4 SATD to calculat the best SATD. The experimental results show that the proposed method achieved 5.08% reduction in encoding time compared to the HEVC test model 12.1 encoder with almost no loss in compression performance.

HEVC의 Transform Skip Mode를 위한 Rough Mode Decision 알고리즘

김영조(Youngjo Kim),김재석(Jaeseok Kim) 대한전자공학회 2014 전자공학회논문지 Vol.51 No.8

HEVC(high efficiency video coding) 표준에서 사용되는 기존의 rough mode decision(RMD) 알고리즘은 transform skip mode(TSM)와는 연관성이 낮은 DCT를 기반으로 하는 모드 선택 방법을 이용하고 있다. 따라서 기존 RMD의 결과로 구한 후보 모드가 TSM에서 사용될 때, 압축 효율이 손실되고 인코딩 시간을 낭비하게 된다. 본 논문은 HEVC에서의 TSM을 위한 새로운 RMD를 제안한다. 우리가 제안한 RMD 알고리즘은 TSM에서 최선의 모드를 선택할 확률을 높이는 새로운 비용 함수를 제안하여 코딩 효율을 향상시킨다. 또한, 제안하는 알고리즘은 새롭게 제안한 임계값을 기준으로 선택 가능성이 거의 없는TSM의 인코딩 과정을 생략하여 인코딩 시간을 줄인다. 실험 결과 제안하는 방식은 HEVC 표준에 비해서 10%의 인코딩 시간을 줄이며 스크린 콘텐츠에 대해서 0.3%의 압축률을 향상시킨다. The existing rough mode decision (RMD) algorithm, used in HEVC standard loses the coding efficiency and wastes encoding time when encoding using transform skip mode (TSM) because the RMD algorithm in HEVC uses a selection method that is designed for DCT, not for TSM. This paper proposes a new RMD algorithm for TSM in HEVC. Our proposed RMD algorithm enhances the coding efficiency by employing a new cost function to increase the probability of selecting the best intra prediction mode for TSM. In addition, it reduces the encoding time by skipping the encoding process of least feasible TSM based on a newly proposed threshold value. The experiment results show that the proposed method achieves coding gains of ?0.3% for screen contents with a 10% reduction in encoding time compared to those of the HEVC standard.

Novel Anti-Reflection Technology for GaAs Single-Junction Solar Cells Using Surface Patterning and Au Nanoparticles

Kim, Youngjo,Lam, Nguyen Dinh,Kim, Kangho,Kim, Sangin,Rotermund, Fabian,Lim, Hanjo,Lee, Jaejin American Scientific Publishers 2012 Journal of nanoscience and nanotechnology Vol.12 No.7

<P>Single-junction GaAs solar cell structures were grown by low-pressure MOCVD on GaAs (100) substrates. Micro-rod arrays with diameters of 2 microm, 5 microm, and 10 microm were fabricated on the surfaces of the GaAs solar cells via photolithography and wet chemical etching. The patterned surfaces were coated with Au nanoparticles using an Au colloidal solution. Characteristics of the GaAs solar cells with and without the micro-rod arrays and Au nanoparticles were investigated. The short-circuit current density of the GaAs solar cell with 2 microm rod arrays and Au nanoparticles increased up to 34.9% compared to that of the reference cell without micro-rod arrays and Au nanoparticles. The conversion efficiency of the GaAs solar cell that was coated with Au nanoparticles on the patterned surface with micro-rod arrays can be improved from 14.1% to 19.9% under 1 sun AM 1.5G illumination. These results show that micro-rod arrays and Au nanoparticle coating can be applied together in surface patterning to achieve a novel cost-effective anti-reflection technology.</P>