• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.39-47
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• 2000

A large scale field test of prefabricated vertical drains is performed to analyze the effect of parameters of the very soft clay at a test site. Compression index and the coefficient of horizontal consolidation obtained by back-analysis from the settlement data were compared with those obtained by means of laboratory tests. The Hyperbolic, Asaoka's and The Curve fitting methods are used to estimate final settlements and coefficients of consolidation. 1. Final settlement predicted with the Hyperbolic method was the largest, and the settlements predicted with the Asaoka's and the Curve fitting methods were nearly the same range, and it was concluded that smear effect has to be considered on design in the case that spacing of drains is small 2. The relationships of the measured consolidation ratio (Urn) and the designed consolidation ratio($U_t$) were showed as $U_m$ = (1.13~1.17)$U_t$, $U_m$ = (1.07~1.20)$U_t$, $U_m$ = (1.13~1.17)$U_t$ on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. The relations on the Asaoka's and the Curve fitting methods were nearly the same range. 3. The relationships of the field compression index($C_{cfield}$) and virgin compression index($V_{cclab}$) were showed as $C_{cfield}$ = (1.26~1.45)$V_{cclab}$, $C_{cfield}$ = (1.08~1.15) $V_{cclab}$, $C_{cfield}$ = (1.04~1.21)$V_{cclab}$, on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. 4. The ratio ($C_h/C_v$) of the coefficient of vertical consolidation and the coefficient of horizontal consolidation that is obtained by back-analysis from the settlement data was $C_h$=(0.7~0.9)$C_v$, $C_h$=(0.9~1.5)$C_v$, $C_h$=(2.4~3.0)$C_v$ on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. 5. It was concluded that the exact consolidation coefficient must be determined after the final settlement is predicted again when the consolidation is finished, because the field consolidation coefficient is decreased as the time allowed to be alone is increased.

• Journal of radiological science and technology
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• v.21 no.1
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• pp.59-64
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• 1998

[ $CaSO_4$ ] thermoluminescent phosphors was made by sintring the $CaSO_4$ after doping the transition elements Tm, Pd, Dy, V, Mo, Zr. The maximum Peaks are found in the measured $CaSO_4$(Tm, Pd, Dy, V, Mo, Zr) TL glow curve at $130^{\circ}C,\;110^{\circ}C,\;140^{\circ}C,\;100^{\circ}C$, and $120^{\circ}C$ when the heating rate is $5^{\circ}C/sec$. The activation energy of the main peak has been estimated by the peak shape method. The estimated activation energies are 1.02eV, 1.32eV, 1.12eV, 0.80eV, and 1.17eV, respectively. The thermoluminescence process in $CaSO_4$(Tm, Pd, Dy, V, Mo, Zr)are found to the 2nd order when the main peak of the glow curve is analyzed by peak shape method. The dose responses of $CaSO_4$(Tm, Pd, Dy, V, Mo, Zr) phosphors are linear within $4{\times}10^{-4}{\sim}1Gy$ of X-rays.

• Journal of the Korean Vacuum Society
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• v.4 no.1
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• pp.109-117
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• 1995

고에너지 이온주입시 격자결함의 생성 및 열처리 거동이 double crystal X-ray와 단면 TEM을 사용하여 연구되었다. 3MeV P+ 이온주입한 실리콘의 DCXRD 분석 결과조사량 증가에 따라 모재 내의 변형량은 증가하였다. HRTEM 분석 결과 고에너지 이온주입시 결함은 표면 부근에 희박하고 Rp 부근에 집중되어 있었다. 또한 이온주입 상태의 결함층은 dark band의 형태로 존재하였으며 열처리시 이차결함은 이곳으로부터 생성됨이 관찰되었다. 3MeV P+,$1X1015extrm{cm}^2$의 조건으로 이온주입된 실리콘 시편의 열처리에 따른 X-ray rocking curve 분석을 통하여 열처리 온도가 $550^{\circ}C$에서 $700^{\circ}C$로 증가함에 따라 모재 내부의 최대 변형량이 7X10-4에서 2.9X10-4으로 감소함이 관찰되었다. 특히 $550^{\circ}C$ 열처리한 시편의 경우 표면으로부터$-1.5mu$m 영역에 작은 변형층이 넓게 잔존하였으며 열처리온도를 $700^{\circ}C$로 증가한 경우 제거되었다. 이온주입시 생성된 일차결함들은 $700^{\circ}C$ 열처리시 $60^{\circ}$ 전위와 <112> 막대 모양 결함, $1000^{\circ}C$ 열처리시 <110>방향의 전위루프로 열처리 조건에 따라 여러 가지 모양의 이차결함으로 변화하였다. 고에너지 이온주입에 의해 발생한 이차결함은 고온에서도 안정하여 고온 열처리에 의한 제거가 용이하지 않았다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.899-900
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• 2009

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.71-74
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• 2000

Pt/Pb$TiO_3$/$SrTiO_3$/p-Si films were prepared by metallo-organic solution deposition(M0SD) method and investigated its structure and ferroelectric properties. Crystallinity of specimen as a funtions of post annealing temperature and the thickness of $SrTiO_3$(STO) buffer layer was studied using XRD and AFM. Based on C-V and P-E curve, $PbTiO_3$(PTO) capacitors showed good ferroelectric hysteresis arising from the polarization switching properties. When the thickness of ST0 buffer layer between PTO and Si substrate was 260 nrn and the post annealing temperature was $650^{\circ}C$, it was showed that production of the pyrochlore phase due to interdiffusion of Si into FTO was prevented. The dielectric constant of FTO thin films calculated from a maximum Cma in the accumulation region was 180 and the dielectric loss was 0.30 at 100 kHz frequency. The memory window in the C-V curve is 1.6V at a gate voltage of 5V.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.10
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• pp.1-6
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• 2010

In this paper, RF Capacitance-Voltage(C-V) curve of short-channel MOSFET has been extracted from the room temperature to $225^{\circ}C$ using a RF method based on measured S-parameter data, and its high-temperature dependent characteristics are empirically modeled. It is observed that the voltage shift according to the variation of temperature in the weak inversion region of RF C-V curves is lower than the threshold voltage shift, but it is confirmed that this phenomenon is unexplainable with a long-channel theoretical C-V equation. The new empirical equation is developed for high-temperature dependent modeling of short-channel MOSFET C-V curves. The accuracy of this equation is demonstrated by observing good agreements between the modeled and measured C-V data in the wide range of temperature. It is also confirmed that the channel capacitance decreases with increasing temperature at high gate voltage.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.225-234
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• 1998

This study was compared the degree of consolidation by Hyperbolic, Curve fitting, Asaoka's, Monden's methods using measured value with theoretical curve in consideration of smear effect and well resistance. The results of the study were summarized as follows ; 1. The degree of consolidation by Hyperbolic method was underestimated than the degree of consolidation by Curve fitting, Asaoka's, and Monden's methods. 2. Typical range of horizontal coefficient of consolidation was $C_h=(2{\sim}3)C_v$ in the case considering smear effect and well resistance, and $C_h=(0.5{\sim}2.5)C_v$ in the case disregarding smear effect and well resistance. 3. The degree of consolidation obtained by ground settlement monitoring was nearly same value when the coefficient of permeability of smear zone by back analysis was shown the half that of in-situ and the diameter of smear zone was shown double that of mendrel. 4. Increasing of diameter reduction ratio of drain, the time of consoildation was delayed. The affection of well resistance the case of small coefficient of permeability was much more than that in the case of large coefficient of permeability. It was recommended that design of diameter reduction of drain consider smear effect and well resistance.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.53-53
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• 2003

Plasma polymerized organic thin films were deposited on Si(100) glass and metal substrates using thiophene and ethylcyclohexane precursors by PECVD method. In order to compare electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30~100 W. AFM showed that the polymer films with smooth surface and sharp interface could be grown under various deposition conditions. Impedance analyzer was utilized for the determination of I-V curve for leakage current density and C-V for dielectric constants, respectively. To obtain C-V curve, we used a MIM structure of metal(Al)-insulator(plasma polymerized thin film)-metal(Pt) structure. Al as the electrode was evaporated on the thiophene films that grew on Pt coated silicon substrates, and the dielectric constants of the as-grown films were then calculated from C- V data measured at 1MHz. From the electrical property measurements such as I-V and C-V characteristics, the minimum dielectric constant and the best leakage current of thiophene thin films were obtained to be about 3.22 and $1{\;}{\times}10^{-11}{\;}A/cm^2$. However, in case of ethylcyclohexane thin films, the minimum dielectric constant and the best leakage current were obtained to be about 3.11 and $5{\;}{\times}10^{-12}{\;}A/cm^2$.

• Journal of the Korean Mathematical Society
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• v.60 no.6
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• pp.1137-1169
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• 2023

Let C be a curve and V → C an orthogonal vector bundle of rank r. For r ≤ 6, the structure of V can be described using tensor, symmetric and exterior products of bundles of lower rank, essentially due to the existence of exceptional isomorphisms between Spin(r, ℂ) and other groups for these r. We analyze these structures in detail, and in particular use them to describe moduli spaces of orthogonal bundles. Furthermore, the locus of isotropic vectors in V defines a quadric subfibration Q_V ⊂ ℙV . Using familiar results on quadrics of low dimension, we exhibit isomorphisms between isotropic Quot schemes of V and certain ordinary Quot schemes of line subbundles. In particular, for r ≤ 6 this gives a method for enumerating the isotropic subbundles of maximal degree of a general V , when there are finitely many.

• Journal of Internet of Things and Convergence
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• v.6 no.2
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• pp.25-29
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• 2020

The elliptic curve crypto-algorithm is widely used in authentication for IoT environment, since it has small key size and low communication overhead compare to the RSA public key algorithm. If the scalar multiplication, a core operation of the elliptic curve crypto-algorithm, is not implemented securely, attackers can find the secret key to use simple power analysis or differential power analysis. In this paper, an elliptic curve scalar multiplication algorithm using a randomized scalar and an elliptic curve point blinding is suggested. It is resistant to power analysis but does not significantly reduce efficiency. Given a random r and an elliptic curve random point R, the elliptic scalar multiplication kP = u(P+R)-vR is calculated by using the regular variant Shamir's double ladder algorithm, where l+20-bit u≡rn+k(modn) and v≡rn-k(modn) using 2^lP=∓cP for the case of the order n=2^l±c.