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PKINIT기반의 Kerberos 인증과 키 교환에 관한 연구 (A study on Kerberos Authentication and Key Exchange based on PKINIT)

  • 신광철;정일용;정진욱
    • 정보처리학회논문지C
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    • 제9C권3호
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    • pp.313-322
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    • 2002
  • 본 논문에서는 IETF CAT Working Group에서 발표한 PKNIT 기반의 인증서비스를 향상시킨 Kerberos 인증 메커니즘을 제안한다. PHNIT기반의 X.509, BS/DNS를 적용하여 영역간의 서비스를 제공하는 인증과 키 교환방식으로 DNS를 통해 외부영역의 위치를 탐색하고 X.509 디렉토리 인증 시스템을 적용, 영역간 체인(CertPath)으로 DNS 서버로부터 공개키를 획득하여 다른 영역을 인증하도록 하였다. 영역간 인증과 키 교환은 Kerberos의 관용키 암호방식을 사용하고 세션 연결은 공개키 방식에 기반을 둔 X.509를 연동시키기 위하여 디렉토리서비스를 이용하였다. 이로써 Client를 확인하기 위한 임의 난수 키($K_{rand}$) 생성과 이로 인한 이중 암호화 과정을 배제하였으며 통신상의 Overload를 감소시키는 효과와 인증절차의 간소화를 가지는 Kerberos 시스템을 설계하였다.

Analysis of Instability Mechanism under Simultaneous Positive Gate and Drain Bias Stress in Self-Aligned Top-Gate Amorphous Indium-Zinc-Oxide Thin-Film Transistors

  • Kim, Jonghwa;Choi, Sungju;Jang, Jaeman;Jang, Jun Tae;Kim, Jungmok;Choi, Sung-Jin;Kim, Dong Myong;Kim, Dae Hwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제15권5호
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    • pp.526-532
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    • 2015
  • We quantitatively investigated instability mechanisms under simultaneous positive gate and drain bias stress (SPGDBS) in self-aligned top-gate amorphous indium-zinc-oxide thin-film transistors. After SPGDBS ($V_{GS}=13V$and $V_{DS}=13V$), the parallel shift of the transfer curve into a negative $V_{GS}$ direction and the increase of on current were observed. In order to quantitatively analyze mechanisms of the SPGDBS-induced negative shift of threshold voltage (${\Delta}V_T$), we experimentally extracted the density-of-state, and then analyzed by comparing and combining measurement data and TCAD simulation. As results, 19% and 81% of ${\Delta}V_T$ were taken to the donor-state creation and the hole trapping, respectively. This donor-state seems to be doubly ionized oxygen vacancy ($V{_O}^{2+}$). In addition, it was also confirmed that the wider channel width corresponds with more negative ${\Delta}V_T$. It means that both the donor-state creation and hole trapping can be enhanced due to the increase in self-heating as the width becomes wider. Lastly, all analyzed results were verified by reproducing transfer curves through TCAD simulation.

Al-MIS(p-Si) 태양전지의 AR Coating 방법 (On the AR Coating Method of Al-MIS(p-Si) Solar Cel)

  • 엄경숙;백수현
    • 대한전자공학회논문지
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    • 제21권6호
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    • pp.64-69
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    • 1984
  • Al-MIS(p-Si)태양전지의 최대 효율은 Al 박막을 0.6A/sec 이하의 속도로 증착시켜 80Å인 두께가 되었을 때임을 알았다. ZnS와 SiO로 AR coating을 했는데, 단층 피막일때는 각각 570Å과 690Å인 박막 두께에서 최대 Isc를 나타냈다. 이는 quarter-coating 조건인 n1d1=λ/4를 만족함을 알았다. 이중층 피막일 때는 한 층을 단층 피막때의 최적 두께를 유지하면서 다른 한 층을 조절했다. 이때의 최대 Isc는 단층피막일 때와 비슷한 값이었으나 넓은 범위의 두께에서 그 값이 그대로 유지되었다. 한편 dzns/ds10=1.9/2.3=570/690인 관계를 유지하면서 총 두께를 각각의 단층피막때의 최적 두께 합에 대해서 70∼90%로 얇게 했을 때 앞에서 논의한 어떤 경우보다도 20%이상의 더 높은 Isc를 얻을 수 있었다 따라서 높은 효율을 얻으면서 정밀한 두께 조절이 불필요한 새로운 AR coating방법을 얻었다.

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한약투여가 소아의 성장에 미치는 영향 (The Effect of Herbal Medicine Treatment on the Growth of Children)

  • 정성민;김덕곤;이진용;조형준
    • 대한한방소아과학회지
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    • 제18권2호
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    • pp.119-126
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    • 2004
  • Objective : We used herbal medicine to treat various disease and also to keep good general condition of children. We aimed to evaluate the effect of herbal medicine on the growth of children treated with herbal medicine. Method: We studied 187 children who visited the department of Pediatrics, KyungHee Oriental Medical Hospital from March 2004 to August 2004. They meet condition as follows; they were treated for more than 6 months and they visited our clinic more than 3 times. Whenever patients visited our hospital, we measured their height, body weight and obesity degree using DS-102(dszenix, Seoul). We measured height percentile of first time visit, and that of last time visit. And we compared them using the Growth Statistics Curve made by the Korean Association of Pediatrics, 1998. Results : The mean growth of total children showed 4.04 percentile upwardly; the growth- up percentile of boys was 4.52 and that of girls was 3.26. Analysis according to disease resulted as follows; children with respiratory disease showed 10.29 percentile growth-up, digestive disease 4.21percentile, urinary disease 4 percentile, allergic disease 2.65 percentile, weak children 2.52 percentile and other disease 3.19 percentile. Conclusion : Herbal medical treatment helped growth not only in children who took medicine for growth retardation problem but children with various disease. Moreover herbal medical treatment applied to keep good general condition of children also gave positive effect on the growth of children.

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일방향응고된 NiAl/$Ni_3Al$ 2상합금의 방향성 측정 및 기계적 특성 평가 (Orientation Measurement and Related Mechanical Properties of Directionally Solidified NiAl/$Ni_3Al$ Two-Phase Alloys)

  • 이혜정;박노진;최환;이재현;오명훈
    • 열처리공학회지
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    • 제23권2호
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    • pp.96-103
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    • 2010
  • $Ni_3Al$ is known as a good high temperature structural material because of high yield strength at ambient temperature. However, it is too brittle to use as a structural material because of their weak grain boundary. In this work, orientation measurement and related mechanical properties of directionally solidified NiAl/$Ni_3Al$ two-phase alloys with various compositions (Ni-23~27 at.%Al) were investigated for developing multi-phase DS-processed alloys with the growth rates of 10, 50 and 100 ${\mu}m/s$ in a modified Bridgeman type furnace. It was found that the multi-phase microstructures such as the $\gamma$ dendrite +${\gamma}'$ matrix duplex microstructure was formed in the hypoeutectic composition of 23 at.%Al, $\beta$ dendrite +${\gamma}'$ matrix duplex microstructure in the hypereutectic composition of 26 and 27 at.%Al. And ${\gamma}'$ single phase was formed in the composition of 24.5 and 25 at.%Al. The hypoeutectic alloy including $\gamma$ dendrites with ${\gamma}'$ matrix showed a large elongation of over 70% at room temperature. However, the room-temperature tensile elongation decreased with increasing Al contents because the volume fraction of brittle $\beta$ dendrites in the ductile ${\gamma}'$ matrix increased.

건설폐토석의 식생용토로서의 이화학적 특성 (Physico-Chemical Properties of the Recycled Waste Soils from Construction Site as Planting Soil)

  • 김원태;윤용한;박봉주
    • 한국환경복원기술학회지
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    • 제10권5호
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    • pp.31-39
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    • 2007
  • This study was carried out to evaluation the recycled waste soils from construction site for planting soil. For this purpose, the concentrations of polluted materials and the physico-chemical properties were measured at recycled soil samples of an industrial waste treating company in the Metropolitan landfill area. The concentrations of polluted materials did not exceed to the standard critical levels of soil pollution in all analyzed items. The measures of the samples soil texture (loamy sand), bulk density (1.09~1.32g/$cm^3$), saturated hydraulic conductivity ($1.6{\times}10^{-3}{\sim}1.8{\times}10^{-3}$cm/sec), solid phase distribution (0.4~0.5$m^3/m^3$), porosity (0.5~0.6$m^3/m^3$), Ex. $K^+$ (1.0~1.2cmol/kg), Ex. $Mg^{2+}$ (0.2~0.6cmol/kg) were identified as not worse than those of conventional planting soil. But the sample soils have serious problems for planting soil such as high levels of pH (9.6~11.5), EC (0.78~1.84ds/m) and Ex. $Ca^{2+}$ (25.6~34.5cmol/kg), low level of organic matter (0.2~0.3%). It is required to improve pH, EC and Ex. $Ca^{2+}$ of sample soils. Consequently, the results suggested a high potential of recycling of the wastes soils for planting soil.

대중저속 무선 통신을 위한 DSSS 모뎀 설계 및 구현 (DSSS MODEM Design and Implementation for a Medium Speed Wireless Link)

  • 원희석;김영식
    • 대한전자공학회논문지TC
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    • 제43권1호
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    • pp.121-126
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    • 2006
  • 본 논문은 9.6kbps 무선 통신용 DSSS CDU방식의 모뎀을 설계 및 제작하였다 개발된 모뎀은 마이크로프로세서에서 신호를 주고받을 수 있도록 범용 인터페이스를 제공한다. 인터페이스는 8비트 데이터버스와 칩 Enable, R/W, 및 인터럽트 핀으로 구성하였다. 송신은 먼저 외부로 8비트 병렬 데이터를 받아 시리얼 데이터로 변환하고 모뎀 내부에서 8 비트 PN-code를 생성하여 Direct Sequence 방식으로 데이터를 76.Bkcps로 확산하여 전송한다 그리고 송수신기의 동기를 위해 8비트 훈련시퀀스를 데이터 프레임 헤드에 첨부하였다. 수신기의 경우 수신된 76.8kcps의 확산된 데이터에서 먼저 PN코드 동기를 찾아낸 후 훈련시퀀스를 이용하여 데이터 동기를 얻어낸다. 이를 위해 Early and Late방식을 이용하였다. 본 논문의 모뎀은 Xilinx FPGA 보드로 구현 및 검증된 후 Hynix $0.25{\mu}m$ CMOS 공정을 이용하여 ASIC 칩으로 제작되었으며, DSSS를 이용한 다중사용자 방식을 사용하였다.

Si CMOS Extension and Ge Technology Perspectives Forecast Through Metal-oxide-semiconductor Junctionless Field-effect Transistor

  • Kim, Youngmin;Lee, Junsoo;Cho, Seongjae
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권6호
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    • pp.847-853
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    • 2016
  • Applications of Si have been increasingly exploited and extended to More-Moore, More-than-Moore, and beyond-CMOS approaches. Ge is regarded as one of the supplements for Si owing to its higher carrier mobilities and peculiar band structure, facilitating both advanced and optical applications. As an emerging metal-oxide device, the junctionless field-effect transistor (JLFET) has drawn considerable attention because of its simple process, less performance fluctuation, and stronger immunity against short-channel effects due to the absence of anisotype junctions. In this study, we investigated lateral field scalability, which is equivalent to channel-length scaling, in Si and Ge JLFETs. Through this, we can determine the usability of Si CMOS and hypothesize its replacement by Ge. For simulations with high accuracy, we performed rigorous modeling for ${\mu}_n$ and ${\mu}_p$ of Ge, which has seldom been reported. Although Ge has much higher ${\mu}_n$ and ${\mu}_p$ than Si, its saturation velocity ($v_{sat}$) is a more determining factor for maximum $I_{on}$. Thus, there is still room for pushing More-Moore technology because Si and Ge have a slight difference in $v_{sat}$. We compared both p- and n-type JLFETs in terms of $I_{on}$, $I_{off}$, $I_{on}/I_{off}$, and swing with the same channel doping and channel length/thickness. $I_{on}/I_{off}$ is inherently low for Ge but is invariant with $V_{DS}$. It is estimated that More-Moore approach can be further driven if Si is mounted on a JLFET until Ge has a strong possibility to replace Si for both p- and n-type devices for ultra-low-power applications.

혐기성 소화조 오니의 탈수에 대한 요인분석 (A Study on Dewatering Characteristics of Anaerobic Digested Sludges)

  • 팽종인
    • 한국환경보건학회지
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    • 제8권2호
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    • pp.13-31
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    • 1982
  • Factors affecting on dewatering characteristics of anaerobically digested or/and elutriated sludges were examined from 15 January 1982 to 30 April 1982, results obtained were as follows 1. Sludges, either anaerobically digested or/and elutriated sludges, which were produced at the Joong Rang Cheon Sewage Treatment Plant wore found to be compressive in its nature, coefficient of compressibility ranged from 0.83 for unelutriated and 1.10 for elutriated. 2. Dosage of FeC13 for the anaerobically digested sludges were difficult to establish for the most favorable dosage rate, though the filterability indicated linear improvement with increased dosage from dosing rate excess of over 15% in terms of dry solids by weight, under the conditions of this examination. Optimum filterability were obtained with 9~11% of $FeCl_3$ for elutriated sludges, and required CaO, as aids, were appeared to be 2.5~3.5 times that of the $FeCl_3$ at that point by weight. 3. The specific resistances for anaerobically digested sludges showed higher value than the elutriated one, being $11 \times 10^{12} ~ 20 \times 10^{12}$ cm/g with no chemical conditioning, and $2 \times 10^{12} ~ 11 \times 10^{12}$ cm/g with conditioned ($FeCl_3$ + CaO) contrast to $0.5 \times 10^{12} ~ 2.0 \times 10cm/g$ for the elutriated. 4. The strength of the alkalinities before and after elutriation were measured to 10,000 ~ 15,000 mg/l and 1,500 ~ 2,000mg/l respectively. These alkalinities affected greatly on the filterabilities together with concentration of the organic matters in the sludges. 5. The yields with 11% $FeCl_3$, by weight to the DS, on the elutriated sludges averaged to $14.7 kg/m^2.hr$, and $3.2kg/m^2.hr$ for unelutriated sludges. Which was 4.6 times of not elutriated sludges. Elutriated sludges without chemical conditioner added showed much better filterabilities than with 15% of $FeCl_3$ added to the anaerobically digested and unelutriated sludges.

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눈깜작임, 증감뇌유발전위와 성격의 상호관계 (Eyeblinks, EP Augmenting / Reducing and Personality)

  • 이성훈
    • 수면정신생리
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    • 제1권2호
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    • pp.156-162
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    • 1994
  • 목 적 : 눈깜작임은 뇌에서 감각을 조절하는 기능과 관계된 개인의 인지능력과 성격에 따라 달라질 수 있다. 저자들은 이러한 성격이 눈깜작임과 증감뇌유발전위 등과 상호 어떠한 연관이 있는지를 연구하려고 하였다. 방법 : 44 명의 정상 대학생에게 증감뇌유발전위, 눈깜작임과 Zuckerman 의 감각추구척도와 Eysenck 성격설문지 동을 조사하여 그 상호관계를 분석하였다. 결 과 : 증감뇌유발전위에서 빛의 강도가 증가할수록 눈깜작임이 증가하였다. 대부분의 성격척도에서 눈깜작임과 유의한 역상관관계를 보였으며 신경증척도만이 정상관관계를 보였다. 눈깜작임과 증감유발전위의 기울기와 가장 강한 정상관관계를 보인 뇌의 부위는 우측 후 측두엽이었다. 결 론 : 감각추구경향이 강할수록 눈을 적게 깜작이었다. 유발전위보다 눈깜작임이 성격과 더 높은 상관관계를 보여 눈깜작임이 더 일차적인 필터 역할을 한다고 생각된다. 그리고 우측 후 측두엽은 여러 뇌 부위 중 시각을 조절하는데 가장 중요한 역할을 하는 것으로 유추된다.

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