• 공업화학
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• 제18권5호
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• pp.449-453
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• 2007

리튬이온이차전지에 사용되는 탄소부극의 성능 향상을 위하여 새로운 탄소부극물질로서 Sn-GIC (Graphite intercalated compound)를 합성하고 그 전기화학적 특성을 조사하였다. 합성시 $SnCl_2$ 수용액의 농도가 증가할수록, 그리고 수용액에 함침한 후 건조한 시료의 열처리 온도가 증가할수록 흑연에 삽입되는 Sn의 함량이 증가하였으며, 또한 흑연 내부로 삽입된 Sn의 함량이 증가함에 따라 이를 부극활물질로 사용한 cell의 초기 방전용량은 증가하였다. 가장 우수한 특성을 나타내는 1.0M $SnCl_2$ 수용액에 함침한 후 $900^{\circ}C$에서 열처리하여 제조한 Sn-GIC는 346 mA/g의 초기용량과 10 cycle 후 13%의 용량감소를 나타내었다.

• Applied Biological Chemistry
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• 제3권
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• pp.1-7
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• 1962

In order to study the rate control step in the protein metabolic course of the chlorophyll formation, the transaminase activities which are obtained freely in the extracts of cotyledons of germinating peas at the light and the dark places, are measured in Beckman mopel D.U, spectrophoto meter at 490 mu. In this case, of two enzymatic reaction products; oxalacetic acid and pyruvic acid, the former is converted to pyruvic acid by aniline citrate and after each pyruvate phenyl hydrazones are extracted by toluenes: when this is treated with strong alcoholic alkali, a colored hydrazone is formed and it is measured by above apparatus. The estimated G.O.T. and G.P.T. in the germinated cotyledons at dark and light places considerably differ in their activities; G.O.T. and G.P.T. activities which are formed at the light are more increased than at the dark and also they differ in their rates through germination, though G.O.T. activity increment is smoothly but that of G.P.T. is more sharply, and they are considered to be directly affected to the chlorophyll formation and indirectly to the growth. G.O.T. and G.P.T. in each fractions of cell in the cotyledons should be formed by dissociation of zymogens in the microsomal fractions and it seems to promoted by light. In the formation of the chlorophyll, the protein metabolism occurred mainly in the microsomal fractions and the rate determining step is found at the point where the zymogene that is able to produce G.P.T. is activated, and this activation is promoted by light as noted above.

• KSBB Journal
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• 제20권2호
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• pp.88-92
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• 2005

인산화 과정은 serine, threonine, tyrosine에서 발생하는 생화학적 반응으로, 본 연구에서는 다양한 응용의 잠재능력이 있는 phosphoserine, phosphothreonine, phosphotyrosine에 대한 엡타머를 개발하였다. 우선 in vitro selection 방법에 의해 combinatorial chemistry로부터 얻어진 RNA library로부터 이들 phosphoamino acids와 친화도를 가지고 있는 엡타머를 찾아낼 수 있었다. 총 10번의 일련 과정을 통해 phosphoserine에 대해서 2.6 nM의 친화도를 가지고 있는 엡타머를 (SeA-06), phosphothreonine에 대해서는 2.7nM의 친화도를 가지고 있는 엡타머 (TrA-18)를 찾아낼 수 있었고, 이들의 RNA 2차 구조를 각각 예측하여 보았다. 그러나 phosphotyrosine의 경우 짧은 길이의 엡타머가 selection됨으로 내부적으로 구조를 가지는 엡타머는 얻을 수 없었다. o-phosphoserine에 대한 항체가 기존에 보고가 되었으나 유사한 구조를 지닌 o-phosphothreonine에도 비슷한 활성을 보여 이들을 구분할 수 있는 리간드를 찾기 힘들었으나, 본 연구에서는 엡타머를 사용한 특이성 조사에서도 서로를 극명하게 구별할 수 있음을 확인할 수 있었다. 이와 같이 발굴된 엡타머를 사용하여 biochip이나 Proteomics 분석 도구의 응용에 큰 기대효과를 제공할 수 있을 것이라 사료된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.54-60
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• 2006

In this paper, we describe a bio-fluidic device for adaptive sample pretreatment, in order to optimize the conditions under which absorbance assays can be conducted. This device can be successfully applied to the measurement of Escherichia coli (E. coli) concentrations using adaptive dilution, with which the dilution ratio can be adjusted during the dilution. Although many attempts have been previously made to miniaturize complex biochemical analyses at the chip scale, very few sample pretreatment processes have actually been miniaturized or automated at this point. Due to the lack of currently available on-chip pretreatments, analytical instruments tend to suffer from a limited range of analysis. This occasionally hinders the direct and quantitative analysis of specific analyses obtained from real samples. In order to overcome these issues, we exploit two novel strategies: dilution with a programmable ratio, and to-and-fro mixing. The bio-fluidic device consists of a rectangular chamber constructed of poly(dimethylsiloxane) (PDMS). This chamber has four openings, an inlet, an outlet, an air control, and an air vent. Each of the dilution cycles is comprised of four steps: detection, liquid drain, buffer injection, and to-and-fro mixing. When using adaptive sample pretreatment, the range in which E. coli concentrations can be measured is broadened, to an optical density (O.D.) range of $0.3{\sim}30$. This device may prove useful in the on-line monitoring of cell concentrations, in both fermenter and aqueous environments.

• Tuberculosis and Respiratory Diseases
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• 제81권2호
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• pp.148-155
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• 2018

Background: Although targeted therapy and immuno-oncology have shifted the treatment paradigm for lung cancer, platinum-based combination is still the standard of care for advanced non-small cell lung cancer (NSCLC). Pemetrexed continuation maintenance therapy has been approved and increasingly used for patients with nonsquamous NSCLC. However, the efficacy of this strategy has not been proven in patients without driving mutations. The objective of this study was to compare the clinical benefit of pemetrexed continuation maintenance to conventional platinum-based doublet in epidermal growth factor receptor (EGFR)-negative lung adenocarcinoma. Methods: A total of 114 patients with EGFR-negative lung adenocarcinoma who were treated with platinum doublet were retrospectively enrolled. We compared the survival rates between patients received pemetrexed maintenance after four-cycled pemetrexed/cisplatin and those received at least four-cycled platinum doublet without maintenance chemotherapy as a first-line treatment. Results: Forty-one patients received pemetrexed maintenance and 73 received conventional platinum doublet. Median progression-free survival (PFS), which was defined as the time from the day of response evaluation after four cycles of chemotherapy to disease progression or death, was significantly higher in the pemetrexed maintenance group compared to conventional group (5.8 months vs. 2.2 months, p<0.001). Median overall survival showed an increasing trend in the pemetrexed maintenance group (22.3 months vs. 16.1 months, p=0.098). Multivariate analyses showed that pemetrexed maintenance chemotherapy was associated with better PFS (hazard ratio, 0.73; 95% confidence interval, 0.15-0.87). Conclusion: Compared to conventional platinum-based chemotherapy, premetrexed continuation maintenance treatment is associated with better clinical outcome for the patients with EGFR wild-type lung adenocarcinoma.

• Clinical and Experimental Reproductive Medicine
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• 제43권2호
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• pp.106-111
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• 2016

Objective: To study the clinical outcomes of single frozen-thawed blastocyst transfer cycles according to the hatching status of frozen-thawed blastocysts. Methods: Frozen-thawed blastocysts were divided into three groups according to their hatching status as follows: less-than-expanded blastocyst (${\leq}EdB$), hatching blastocyst (HgB), and hatched blastocyst (HdB). The female age and infertility factors of each group were evaluated. The quality of the single frozen-thawed blastocyst was also graded as grade A, tightly packed inner cell mass (ICM) and many cells organized in the trophectoderm epithelium (TE); grade B, several and loose ICM and TE; and grade C, very few ICM and a few cells in the TE. The clinical pregnancy and implantation rate were compared between each group. The data were analyzed by either t-test or chi-square analysis. Results: There were no statistically significant differences in average female ages, infertility factors, or the distribution of blastocyst grades A, B, and C in each group. There was no significant difference in the clinical pregnancy and implantation rate of each group according to their blastocyst grade. However, there was a significant difference in the clinical pregnancy and implantation rate between each group. In the HdB group, the clinical pregnancy and implantation rate were similar regardless of the blastocyst quality. Conclusion: There was an effect on the clinical outcomes depending on whether the blastocyst hatched during single frozen-thawed blastocyst transfer. When performing single frozen-thawed blastocyst transfer, the hatching status of the frozen-thawed blastocyst may be a more important parameter for clinical outcomes than the quality of the frozen-thawed blastocyst.

• 한국정보통신학회논문지
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• 제22권1호
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• pp.109-116
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• 2018

전자서명, 인증 코드, 키 생성 알고리듬 등의 보안 프로토콜에 사용되는 SHA-256 해시 함수를 면적 효율적으로 설계하였다. 설계된 SHA-256 해시 프로세서는 입력 메시지에 대한 패딩 및 파싱 기능을 수행하는 패더 블록을 포함하여 프리프로세싱을 위한 소프트웨어 없이 동작하도록 구현하였다. 라운드 연산을 16-비트 데이터 패스로 구현하여 64 라운드 연산이 128 클록 주기에 처리되도록 하였으며, 이를 통해 저면적 구현과 함께 성능 대비 하드웨어 복잡도 (area per throughput; APT)를 최적화 하였다. 설계된 SHA-256 해시 프로세서는 Virtex5 FPGA로 구현하여 정상 동작함을 확인하였으며, 최대 116 MHz 클록 주파수로 동작하여 337 Mbps의 성능을 갖는 것으로 평가되었다. ASIC 구현을 위해 $0.18-{\mu}m$ CMOS 셀 라이브러리로 합성한 결과, 13,251 GE로 구현되었으며, 최대 동작주파수는 200 MHz로 예측되었다.

• 한국태양에너지학회 논문집
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• 제38권1호
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• pp.45-55
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• 2018

Environmentally benign lead-free solder coated ribbon (e. g. SnCu, SnZn, SnBi${\cdots}$) has been intensively studied to interconnect cells without lead mixed ribbon (e. g. SnPb) in the crystalline silicon(c-Si) photovoltaic modules. However, high melting point (> $200^{\circ}C$) of non-lead based solder provokes increased thermo-mechanical stress during its soldering process, which causes early degradation of PV module with it. Hence, we proposed low-temperature conductive paste (CP) based tabbing method for lead-free ribbon. Modules, interconnected by the lead-free solder (SnCu) employing CP approach, exhibits similar output without increased resistivity losses at initial condition, in comparison with traditional high temperature soldering method. Moreover, 400 cycles (2,000 hour) of thermal cycle test reveals that the module integrated by CP approach withstands thermo-mechanical stress. Furthermore, this approach guarantees strong mechanical adhesion (peel strength of ~ 2 N) between cell and lead-free ribbons. Therefore, the CP based tabbing process for lead free ribbons enables to interconnect cells in c-Si PV module, without deteriorating its performance.

• 대한전자공학회논문지SD
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• 제44권7호통권361호
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• pp.45-53
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• 2007

본 논문에서는 실시간 HD급 영상($1920{\times}1080@30fps$) 처리를 위한 효율적인 CAVLC (Context-based Adaptive Variable Length Code) 부호화기의 하드웨어 구조를 제안한다. 기존에 제안되었던 CAVLC 하드웨어 구조들은 CAVLC 부호화를 위해 필요한 $4{\times}4$ 블록내의 정보들을 구하기 위해서 16개의 계수들을 모두 탐색하면서 zigzag scanning을 하였다. 그러나 zigzag 방향으로 정렬 된 계수들 중 '0'이 아닌 마지막 계수 이후에 존재하는 '0'의 열은 CAVLC 부호화를 하는데 있어 불필요한 계수들이다. 본 논문에서는 이러한 불필요한 연산을 줄이기 위해서 계수 위치 탐색 기법과 레벨 순차 정렬 기법을 제안한다. 제안된 구조를 적용하여 실험한 결과, 하나의 매크로블록을 처리하는 평균 클럭 수(Cycles/MB)는 기존 방식보다 약 23%가 줄었다. 제안된 CAVLC 하드웨어 구조는 Verilog HDL을 사용하여 하드웨어로 설계 및 검증되었다. 0.18um 표준 셀 라이브러리로 합성한 결과 16.3k 게이트를 가졌고, HD급($1920{\times}1080@30fps$) 영상을 기준으로 했을 경우 81MHz에서 동작할 수 있음을 확인하였다.

• 한국정보통신학회논문지
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• 제9권8호
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• pp.1741-1748
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• 2005

본 논문에서는 암호 기능과 함께 데이터 인증 기능을 지원하는 OCB(offsetest codebook)-AES(advanced encryption) 암호 알고리즘을 VLSI로 설계하고 성능을 분석하였다. OCB-AES 암호 알고리즘은 기존 암호 시스템에서 암호 알고리즘과 인증에 구별된 알고리즘과 하드웨어를 사용함에 따른 많은 연산 시간과 하드웨어 문제를 해결하였다. 면적 효율적인 모듈화된 오프셋 생성기와 태그 생성 회로를 내장한 OCB-AES 프로세서는 IDEC 삼성 0.35um CMOS 공정으로 설계되었으며 약 55,700 게이트로 구성되며, 80MHz의 동작주파수로 930 Mbps의 암${\cdot}$복호율을 갖는다. 그리고 무결성과 인증에 사용되는 128 비트 태그를 생성하는데 소요되는 클록사이클 수는 (m+2)${\times}$(Nr+1)이다. 여기서 m은 메시지의 블록 수이며, Nr은 AES 암호 알고리즘의 라운드 수이다. 설계된 프로세서는 높은 암${\times}$복효율과 면적 효율성으로 IEEE 802.11i 무선 랜과 모바일용 SoC(System on chip)에 암호 처리를 위한 소프트 IP(Intellectual Property)로 적용 가능하다.