• Title/Summary/Keyword: C.V.A.

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Annealing Effects on Concentration Profiles of Deep Energy Levels in Platinum-diffused Silicon (백금 확산 실리콘의 깊은 에너지 준위의 농도분포에 대한 열처리효과)

  • Kwon, Young-Kyu
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.3
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    • pp.207-212
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    • 2007
  • The concentration profiles of deep energy levels($E_c$ -0.23e V, $E_v$+0.36e V and $E_c$ -0.23e V) in platinum-diffused silicon have generally a sharp gradient in the vicinity of the surface of the silicon wafer. In this work two efficient methods are proposed to obtain the uniform concentration profiles throughout the silicon wafer. One is that the platinum diffusion is carried out at $1000^{\circ}C$ for 1h in oxygen atmosphere. In this case the values of obtained uniform concentration, $1{\times}10^{15}cm^{-3}$ for the $E_c$ -0.23e V level, and 1{\times}10^{14}cm^{-3}$ for the $E_c$ -0.52e V level, are very restricted, respectively. The other is two-step annealing process. The platinum diffusion is carried out at $850{\sim}1100^{\circ}C$ in a nitrogen ambient for 1h and then the annealing is performed at $1000^{\circ}C$ in oxygen ambient after removing platinum-source from the platinum diffused samples. The advantage of this method is that the uniform concentration of these levels required power devices can be controlled by setting the desired temperatures when the platinum diffusion is carried out in nitrogen ambient.

Design and Implementation of the CDMA2000 1x EV-DO Security Layer to which applies 3GPP2 C.S0024-A v.2.0 Standard (3GPP2 C.S0024-A v.2.0 표준을 적용한 CDMA2000 1x EV-DO 보안 계층 설계 및 구현)

  • Yang, Jong-Won;Cho, Jin-Man;Lee, Tae-Hoon;Seo, Chang-Ho
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.1
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    • pp.59-65
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    • 2008
  • In security layer in the CDMA2000 1x EV-DO, a standard - C.S0024-a v2.0 is being accomplished under the project of 3GPP2(3rd Generation Partnership Project2). Therefore, a security device is needed to implement the security layer which is defined on the standard document for data transfer security between AT(Access Terminal) and AN(Access Network) on CDMA2000 1x EV-DO environment. This paper realizes the security layer system that can make safe and fast transfer of data between AT and AN. It could be applied to various platform environments by designing and implementing the Security Layer in the CDMA2000 1x EV-DO Security Layer to which applies C.S0024-A v2.0 of 3GPP2.

Voltage Fluctuation of a Nb/Al-Al$O_{x}$/Nb Tunnel Junction Observed at the Gap Voltage (갭전압에서 나타난 Nb/Al-Al$O_{x}$/Nb 터널 접합의 전압 요동 현상)

  • 홍현권;김규태;박세일;김구현;남두우
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.123-126
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    • 2002
  • Samples of Nb/Al-Al$O_{x}$/Nb tunnel junction with the size of 50$\mu$m $\times$ 50$\mu$m were fabricated by employing self-aligning and reactive ion etching technique. In the samples with high-quality, $V_{m}$ value (the product of the critical current and subgap resistance measured at 2 mV) was 34 mV at the critical current density $J_{c}$ = 500 A/$cm^{2}$ and $V_{g}$ value (the gap voltage) was 2.8 mV. In the higher $J_{c}$, voltage fluctuation in the current rising at the gap voltage was observed. The $V_{m}$ and $J_{c}$ value were 8 mV and 900 A/$cm^{2}$, respectively.

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The Performance of Li/V6O13 Lithium Polymer Battery (Li/V6O13 리튬 폴리머 전지의 성능)

  • Kim, Hyung-Sun;Cho, Byung-Won;Yun, Kyung-Suk;Chun, Hai-Soo
    • Applied Chemistry for Engineering
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    • v.7 no.2
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    • pp.362-370
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    • 1996
  • The performance of The performance of $Li/V_6O_{13}$ cell and the electrochemical properties of polymer electrolyte based on poly(acrylonitrile)[PAN] was investigated. The ionic conductivity of polymer electrolyte showed $2.3{\times}10^{-3}S/cm$ and the compatibility with lithium electrode was excellent. Also, it showed the electrochemical stability up to 4.3V(vs. $Li^+/Li$). The cell reaction of $Li/V_6O_{13}$ was dominated by the interfacial resistance between $V_6O_{13}$ electrode and polymer electrolyte. The diffusion coefficient of lithium ion within $V_6O_{13}$ was $2.7{\times}10^{-9}{\sim}4.2{\times}10^{-8}cm^2/sec$. The utilization of $V_6O_{13}$ active material was 95% at C/8($50{\mu}A/cm^2$) and 82% at C/4($100{\mu}A/cm^2$), respectively.

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SR proteins regulate V6 exon splicing of CD44 pre-mRNA

  • Loh, Tiing Jen;Moon, Heegyum;Jang, Ha Na;Liu, Yongchao;Choi, Namjeong;Shen, Shengfu;Williams, Darren Reece;Jung, Da-Woon;Zheng, Xuexiu;Shen, Haihong
    • BMB Reports
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    • v.49 no.11
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    • pp.612-616
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    • 2016
  • CD44 pre-mRNA includes 20 exons, of which exons 1-5 ($C_1-C_5$) and exons 16-20 ($C_6-C_{10}$) are constant exons, whereas exons 6-15 ($V_1-V_{10}$) are variant exons. $V_6$-exon-containing isoforms have been known to be implicated in tumor cell invasion and metastasis. In the present study, we performed a SR protein screen for CD44 $V_6$ splicing using overexpression and lentivirus-mediated shRNA treatment. Using a CD44 $V_6$ minigene, we demonstrate that increased SRSF3 and SRSF4 expression do not affect $V_6$ splicing, but increased expression of SRSF1, SRSF6 and SRSF9 significantly inhibit $V_6$ splicing. In addition, using a constitutive exon-specific primer set, we could not detect alterations of CD44 splicing after SR protein-targeting shRNA treatment. However, using a $V_6$ specific primer, we identified that reduced SRSF2 expression significantly reduced the $V_6$ isoform, but increased $V_{6-10}$ and $V_{6,8-10}$ isoforms. Our results indicate that SR proteins are important regulatory proteins for CD44 $V_6$ splicing.

A Study on the Objectives of Cultural Property Education for establish of the U.V.E.C.(Understand, Value, Enjoy, Create) Cultural Property Education (U.V.E.C.(Understand, Value, Enjoy, Create) 문화재교육 정립을 위한 문화재교육 목표 연구)

  • PARK Sanghye
    • Korean Journal of Heritage: History & Science
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    • v.55 no.4
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    • pp.278-294
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    • 2022
  • To date, cultural property education has seen rapid quantitative growth due to national and personal needs. However, qualitative growth is lacking. The objectives of cultural property education have not been established, and therefore, even its identity is not clear. The most pressing issue at present in cultural property education is to first set objectives. This study aimed to analyze the objectives of current cultural property education, identify the problems, and set new objectives to meet significant national and personal needs in terms of education. The problems with the objectives of current cultural property education are that the persons interested in the education do not understand the concept of the education objectives clearly and that the objectives do not contain much actual content of the education. Also, the objectives of the education do not take into account the dynamic competencies and interests of the learners and do not satisfy the changes of the times. To solve these problems, new cultural property education, called 'U.V.E.C.,' was offerred. U.V.E.C. education is aimed at understanding cultural properties, recognizing their value, and enjoying them, and at creating culture. The objectives of U.V.E.C. cultural property education were set such that they can be modified flexibly in a learner-centric way with clear and practical format and contents. Based on this direction, stepwise objectives were set including overall objectives, detailed objectives, and practice objectives, and objective cases of each step were proposed. Considering the generality of the education and the distinct characteristics of the cultural properties, the U.V.E.C. education objectives took into account the diversity of behavioral objectives, clearness in statements, the objectives of problem solving, the initiative of learners and openness for expression outcomes. The U.V.E.C. objectives are clear and specific so that teachers can enhance their pedagogical efficiency and learners are able to develop interesting and diversified competencies. In addition, it is expected that the U.V.E.C. objectives will significantly affect objective setting for education on cultural properties which have not been studied widely. Further systemic and specific studies on the contents and methods of the U.V.E.C. education would help to change the overall education on cultural properties and position the field as a new academic area.

Stimulation of Cephalosporin C Production by Acremonium chrysogenum M35 with Fatty Acids

  • Kim Jong-Chae;Kang Seong-Woo;Lim Jung-Soo;Song Yoon-Seok;Kim Seung-Wook
    • Journal of Microbiology and Biotechnology
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    • v.16 no.7
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    • pp.1120-1124
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    • 2006
  • Supplementation with rice oil and its major components (oleic acid and linoleic acid) was found to have a significant influence on cephalosporin C (CPC) production and cell growth by A. chrysogenum M35 in shake flask cultures. Five percent (v/v) rice oil had the most robust effect and 5% (v/v) oleic acid was the second most efficient on cell growth, whereas 3% (v/v) linoleic acid was found to be optimal for CPC production. Rice oil, oleic acid, and linoleic acid also significantly improved the rates of glucose consumption. When glucose was almost consumed, CPC production was initiated and, on the addition of rice oil, lipase activity increased steadily to 1.56 U/ml for 4 days. These results suggest that rice oil and fatty acids are used as carbon source to produce CPC by A. chrysogenum M35. Moreover, a mixture, composed of 40% (v/v) oleic acid and 60% (v/v) linoleic acid, had the strongest stimulatory effect on CPC production, due to a synergistic effect of the two fatty acids. Consequently, the maximum CPC titer (7.44 g/l) was improved about 4.5-fold.

Electrical and Microstructure Properties on Sintering Conditions of ZnO Varistor (소결 조건에 따른 ZnO 바리스터의 미세구조 및 전기적 특성)

  • Yoon, Jung-Rag;Chung, Tae-Serk;Lee, Heun-Young;Lee, Serk-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.7
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    • pp.662-666
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    • 2006
  • Microstructure and electrical properties of ZnO varistors as a function of sintering temperature and times were investigated. Sintering temperature and times greatly affected electrical properties and Bi-rich liquid phase of the microstructure. The varistor which were sintered at $1125^{\circ}C\sim1150^{\circ}C$, for 2 hr exhibited the varistor voltage$(V_c)$, nonlinear coefficient $(V_{10mA}/V_{1mA})$, leakage current$(I_L)$ dielectric constant and dissipation factor as $225\sim250V/mm,\;0.89\sim0.92,\;0.8\sim1.1{\mu}A,\;720\sim740\;and\;1.8\sim2.0%$, respectively.

Effect of Vapor-dam Treatment and End-coating Treatment on the air Circulating oven Drying Characteristics of Green Stocks for Korean Traditional Double-headed Drum (수증기댐처리 및 엔드코팅처리가 장고용 초갈이재의 송풍오븐건조 특성에 미치는 영향)

  • Lee, Nam-Ho;Jung, Hee-Suk;Hayashi, Kazuo;Li, Cheng-Yuan;Zhao, Xue-Feng;Hwang, Ui-Do
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.1
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    • pp.17-26
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    • 2007
  • This study was conducted to investigate the effects of End-coating (CO) treatment and Vapor-dam (V) treatment on the air circulating oven drying characteristics of green stock (Paulownia tomentosa) for drum. The reduction of the weight of specimens was greatly displayed in order of control (C-NC) treatment, End-coating (C-CO) treatment, Vapor-dam (V-NC) treatment and Vapor-dam/End-coating (V-CO) treatment after the beginning of drying. The V-CO treated specimen showed smoother temperature gradient compared with the V-NC treated specimen throughout whole drying stage and there was little temperature gradient between the inner and outer part of the cylindrical stock. The C-CO treated specimen showed higher value of vapor pressure in both the inner and outer part of the cylindrical stock until the middle stage of drying, while after the middle stage of drying only the inner part of the cylindrical stock presented higher value compared with the C-NC treated specimen. The distribution of the absolute vapor pressure of the V-CO treated specimen was similar to that of the V-NC treated specimen during the initial stage of drying. However, the former showed a large distribution in order of the hollow, the outer part, the inner part of the cylindrical stock after the initial stage of drying, which was entirely different model of distribution from that of the V-NC treated specimen. Surface checks and ring failures were not observed for all of the specimens, while end checks were severely occurred for the C-NC treated specimen and the V-NC treated specimen.