• Title/Summary/Keyword: SC2

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Spectrophotometric Determination of Scandium(III) with Eriochrome Cyanine R in the Presence of Cetyltrimethylammonium bromide (Cetyltrimethylammonium bromide에서 Eriochrome Cyanine R에 의한 스칸듐(III)의 분광광도법 정량)

  • Cha, Ki-Won;Park, Chan-Il;Kim, Jong-Whon
    • Analytical Science and Technology
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    • v.9 no.2
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    • pp.139-144
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    • 1996
  • The spectrophotometric determination method of scandium with eriochrome cyanine R(ECR) and the composition ratio of the complex were investigated in the presence of surfactants. The absorbance increase and red shift of maximum adsorption wavelength of Sc(III)-ECR complex were observed in cetyltrimethylammonium bromide (CTMAB), but those changes were not observed in the sodium dodecyl sulfate(SDS) and Triton X-100. A volume of 5ml of $1{\times}10^{-3}M$ ECR and 10ml of $2{\times}10^{-4}M$ CTMAB are necessary for the determination of $1{\times}10^{-7}{\sim}3.0{\times}10^{-6}M$ Sc(III) at pH 6.5. The apparent molar absorption coefficient of the Sc(III)-ECR-CTMAB, temary complex at 610nm is $5.6{\times}10^5mol^{-1}cm^{-1}L$ and its detection limit is $1.0{\times}10^{-7}M$. The binary complex composition of Sc(III)-ECR is 1:2 and the ternary complex composition of Sc(III)-ECR-CTMAB is 1:3:1.

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A Study on Efficient CNU Algorithm for High Speed LDPC decoding in DVB-S2 (DVB-S2 기반 고속 LDPC 복호를 위한 효율적인 CNU 계산방식에 관한 연구)

  • Lim, Byeong-Su;Kim, Min-Hyuk;Jung, Ji-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.9
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    • pp.1892-1897
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    • 2012
  • In this paper, efficient CNU(Check Node Update) algorithms are analyzed for high speed LDPC decoding in DVB-S2 standard. In aspect to CNU methods, there are some kinds of CNU methods. Among of them, MP (Min Product) method is quite often used in LDPC decoding. However MP needs LUT (Look Up Table) that is critical path in LDPC decoding speed. A new SC-NMS (Self-Corrected Normalized Min-Sum) method is proposed in the paper. NMS needs only normalized scaling factor instead of LUT and compensates the overestimation of MP approximation. In addition, SC method is proposed. It gives a faster convergence toward a decoded codeword. If a message change its sign between two iterations, it is not reliable and to avoid to propagate noisy information, its module is set to 0. The performance of SC-NMS has a little degrade compare to MP by 0.1 dB, however considering computational complexity and decoding speed, SC-NMS algorithm is optimal method for CNU algorithm.

Performance Analysis of DS/CDMA with Hybrid SC/MRC over Nakagami Fading Channel (나카가미 페이딩 채널하에서 Hybrid SC/MRC를 가진 DS/CDMA 성능분석)

  • 김원섭;박진수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.7A
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    • pp.477-484
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    • 2003
  • In this paper, we compared and analyzed the influence of the fading index and the number of branch of diversity in the Nakagami-m fading channel environment when the MRC diversity and the hybrid SC/MRC are applied to the DS/CDMA system. We considered that the number of branches were 2,3, and 4, respectively and applied an individual diversity type according to the number of branches, when nakagami fading index(m) were 1 and 2. We found that when the Nakagami fading index m is small, that is to say, when fading is inferior, the application of a hybrid SC/MRC diversity Rake receiver is efficient; however, when the fading environment is good, the application of the MRC diversity Rake receiver is efficient. As a result, we verified that when the actual communication environment is inferior, the hybrid SC/MRC diversity that selects a strong signal to be received on an individual number of branches could replace the MRC diversity, as a method to achieve a similar performance by reducing the complexity of the system.

Student Research Programs in U.S. Medical Schools and Institutions (미국 의학교육기관의 학생연구 프로그램)

  • Kim, Seok Yong
    • Korean Medical Education Review
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    • v.17 no.2
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    • pp.60-68
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    • 2015
  • The majority of medical educators agree that scientific education is critical to the development of physician-scientists. However, the proportion of physicians interested or engaged in research has been decreasing. To overcome this deficit of research oriented physicians, many medical schools in the United States have introduced scholarly concentration (SC) programs into their medical curricula since 2000. In contrast, Korea has very few medical schools with such programs. Research programs at American medical schools were surveyed and investigated in order to better design and develop SC programs appropriate for Korean medical schools. Information on SC programs was gathered by reviewing medical school web sites and related articles. The SC programs of Brown Alpert Medical School, University of Pittsburgh School of Medicine, Duke University School of Medicine, and Stanford University School of Medicine are discussed in depth. The characteristics of each program were organized into seven parts: program description, administrative structure, orientation, curricular content, mentors and mentoring, student evaluation, and challenges. For a successful SC program in Korea we must consider providing guaranteed time for SC programs with necessary modifications in the core medical curriculum, educating and training of mentors, providing orientation and motivating students to pursue research, developing curricula for SC programs, and evaluating the progress of SC projects.

Administration of Aqueous Extract of Schizandra chinensis Fruit Inhibits the Experimental Colitis in Mice

  • Kang, Chon-Sik;Tae, Jin;Ham, Seong-Ho;Kim, Dae-Ki;Lee, Young-Mi;Lee, Kang-Soo;Yun, Yong-Gab
    • Natural Product Sciences
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    • v.13 no.1
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    • pp.78-84
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    • 2007
  • Schizandra chinensis fruits (SC) have been used as a traditional Oriental medicine for treatments of many stress-induced diseases. In the present study, we investigated the protective effect of SC aqueous extract(SC-Ex) in the inflammatory diseases of intestine using a mouse model of ulcerative colitis. An experimental colitis was induced by daily treatment with 5% dextran sulfate sodium (DSS). SC-Ex was orally administered from day 2 of DSS treatment in a dose-dependent manner. Administration of SC-Ex reduced significantly clinic signs of DSS-induced colitis, including body weight loss, shorten colon length, increased disease activity index, and histological colon injury. Moreover, SC-Ex suppressed significantly not only the activities of myeloperoxidase (MPO) and chymase, but also the expressions of $TNF-{\acute{a}}$ and COX-2 in DSS-treated colon tissues. Inhibitory effect of SC-Ex was effective at a dose over 20 mg/kg. Our results indicate that SC-Ex may possess therapeutic effect on the development of DSS-induced colitis.

Investigation of Li Dopant as a Sintering Aid for ScSZ Electrolyte for IT-SOFC

  • Mori, Masashi;Liu, Yu;Ma, Shuhua;Hashimoto, Shin-ichi;Takei, Katsuhito
    • Journal of the Korean Ceramic Society
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    • v.45 no.12
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    • pp.760-765
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    • 2008
  • In this study, the effects of small amounts (${\leq}3\;mol%$) of Li doping on the sintering characteristics and electrochemical performance of $(ZrO_2)_{0.89}(ScO_{1.5})_{0.1}(CeO_2)_{0.01}$ (ScSZ) were investigated. By adding 3 mol% lithium, the densification temperature of ScSZ was reduced from the conventional temperature of $1400^{\circ}C$ to $1200^{\circ}C$. It was found that Li doping also led to changes in the Zr:Sc ratio at the grain boundaries. Correspondingly, the dispersion of lithium zirconia at the grain boundaries accelerated the growth of ScSZ grains and increased the grain boundary resistance at temperatures below $450^{\circ}C$. At elevated temperatures of $450{\sim}750^{\circ}C$, the electrical conductivity of the ScSZ after doping remained almost unchanged under air and reducing atmospheres. These results suggest that the addition of lithium is promising for use in low temperature co-firing of ScSZ-based components for intermediate temperature solid oxide fuel cells.

Antifungal activity of Saccharomyces cerevisiae peroxisomal 3-ketoacyl-CoA thiolase

  • Lee, Jung-Ro;Kim, Sun-Young;Chae, Ho-Byoung;Jung, Ji-Hyun;Lee, Sang-Yeol
    • BMB Reports
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    • v.42 no.5
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    • pp.281-285
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    • 2009
  • Peroxisomes play an important role in cellular defense systems and generate secondary messengers for cellular communication. Saccharomyces cerevisiae containing oleate-induced peroxisomes were subjected to buffer-soluble extraction and two chromatographic procedures, and a protein with antifungal activity was isolated. The results of MALDI-TOF analysis identified the isolated protein as peroxisomal 3-ketoacyl-CoA thiolase (ScFox3). Purified yeast ScFox3 exhibited thiolase activity that catalyzed the thiolytic cleavage of 3-ketoacyl-CoA to acetyl-CoA and acyl-CoA. ScFox3 protein inhibited various pathogenic fungal strains, with the exception of Aspergillus flavus. Using ScFox3-GFP and PTS2 signal-truncated ScFox3M-GFP, we showed that only ScFox3-GFP, with an intact PTS2 peroxisome signal sequence, was able to translocate into peroxisomes. Yeast ScFox3 is a natural antifungal agent found in peroxisomes.

Investigation of Damping Ratio of Steel Plate Concrete (SC) Shear Wall by Lateral Loading Test & Impact Test (횡방향 가력실험 및 충격실험을 통한 강판콘크리트(SC) 전단벽의 감쇠비 평가)

  • Cho, Sung Gook;So, Gi Hwan;Park, Woong Ki
    • Journal of the Earthquake Engineering Society of Korea
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    • v.17 no.2
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    • pp.79-88
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    • 2013
  • Steel plate concrete (SC) composite structure is now being recognized as a promising technology applicable to nuclear power plants as it is faster and suitable for modular construction. It is required to identify its dynamic characteristics prior to perform the seismic design of the SC structure. Particularly, the damping ratio of the structure is one of the critical design factors to control the dynamic response of structure. This paper compares the criteria for the damping ratios of each type of structures which are prescribed in the regulatory guide for the nuclear power plant. In order to identify the damping ratio of SC shear wall, this study made SC wall specimens and conducted experiments by cyclic lateral load tests and vibration tests with impact hammer. During the lateral loading test, SC wall specimens exhibited large ductile capacities with increasing amplitude of loading due to the confinement effects by the steel plate and the damping ratios increased until failure. The experimental results show that the damping ratios increased from about 6% to about 20% by increasing the load from the safe shutdown earthquake level to the ultimate strength level.

Effect of SC-1 Cleaning to Prevent Al Diffusion for Ti Schottky Barrier Diode (Ti 쇼트키 배리어 다이오드의 Al 확산 방지를 위한 SC-1 세정 효과)

  • Choi, Jinseok;Choi, Yeo Jin;An, Sung Jin
    • Korean Journal of Materials Research
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    • v.31 no.2
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    • pp.97-100
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    • 2021
  • We report the effect of Standard Clean-1 (SC-1) cleaning to remove residual Ti layers after silicidation to prevent Al diffusion into Si wafer for Ti Schottky barrier diodes (Ti-SBD). Regardless of SC-1 cleaning, the presence of oxygen atoms is confirmed by Auger electron spectroscopy (AES) depth profile analysis between Al and Ti-silicide layers. Al atoms at the interface of Ti-silicide and Si wafer are detected, when the SC-1 cleaning is not conducted after rapid thermal annealing. On the other hand, Al atoms are not found at the interface of Ti-SBD after executing SC-1 cleaning. Al diffusion into the interface between Ti-silicide and Si wafer may be caused by thermal stress at the Ti-silicide layer. The difference of the thermal expansion coefficients of Ti and Ti-silicide gives rise to thermal stress at the interface during the Al layer deposition and sintering processes. Although a longer sintering time is conducted for Ti-SBD, the Al atoms do not diffuse into the surface of the Si wafer. Therefore, the removal of the Ti layer by the SC-1 cleaning can prevent Al diffusion for Ti-SBD.

The Synchronization and Secure Communication of Hyper-chaos circuit using SC-CNN (SC-CNN을 이용한 하이퍼카오스 회로에서의 동기화 및 비밀 통신)

  • 배영철;김주완
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.7
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    • pp.1064-1068
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    • 2002
  • In this paper, we introduce a hyper-chaos synchronization method using State-Controlled Cellular Neural Network(SC-CNN). We make a hyper-chaos circuit using SC-CNN with the n-double scroll. A hyper-chaos circuit is created by applying identical n-double scrolls with weak coupled method, to each cell. Hyper-chaos synchronization was achieved using drive response synchronization between the transmitter and receiver about each state in the SC-CNN. From the result of the recovery signal through the demodulation method in the receiver, We shown that recovery quality of state variable $$\chi$_3$ is superior to that of ${$\chi$_2}, {$\chi$_1}$ in secure communication.