• Investigative Magnetic Resonance Imaging
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• v.20 no.2
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• pp.81-87
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• 2016

Purpose: To analyze the feasibility of three-dimensional (3D) diffusion-weighted (DW) PSIF (reversed FISP [fast imaging with steady-state free precession]) sequence in order to evaluate peripheral nerves in the elbow. Materials and Methods: Ten normal, asymptomatic volunteers were enrolled (6 men, 4 women, mean age 27.9 years). The following sequences of magnetic resonance images (MRI) of the elbow were obtained using a 3.0-T machine: 3D DW PSIF, 3D T2 SPACE (sampling perfection with application optimized contrasts using different flip angle evolution) with SPAIR (spectral adiabatic inversion recovery) and 2D T2 TSE (turbo spin echo) with modified Dixon (m-Dixon) sequence. Two observers used a 5-point grading system to analyze the image quality of the ulnar, median, and radial nerves. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of each nerve were measured. We compared 3D DW PSIF images with other sequences using the Wilcoxon-signed rank test and Friedman test. Inter-observer agreement was measured using intraclass correlation coefficient (ICC) analysis. Results: The mean 5-point scores of radial, median, and ulnar nerves in 3D DW PSIF (3.9/4.2/4.5, respectively) were higher than those in 3D T2 SPACE SPAIR (1.9/2.8/2.8) and 2D T2 TSE m-Dixon (1.7/2.8/2.9) sequences (P < 0.05). The mean SNR in 3D DW PSIF was lower than 3D T2 SPACE SPAIR, but there was no difference between 3D DW PSIF and 2D T2 TSE m-Dixon in all of the three nerves. The mean CNR in 3D DW PSIF was lower than 3D T2 SPACE SPAIR and 2D T2 TSE m-Dixon in the median and ulnar nerves, but no difference among the three sequences in the radial nerve. Conclusion: The three-dimensional DW PSIF sequence may be feasible to evaluate the peripheral nerves around the elbow in MR imaging. However, further optimization of the image quality (SNR, CNR) is required.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.209.2-209.2
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• 2005

• Bulletin of the Korean Chemical Society
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• v.5 no.1
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• pp.16-21
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• 1984

The relative Arrhenius parameters for t-butoxy radical decomposition (log $A_d$, $E_d$) and hydrogen abstraction of t-butoxy radical from hydrogen donor (log $A_d$, $E_d$) by competitive method were obtained as follows: for cyclohexane; log $A_a/A_d$ = -4.17 mole/l and $E_d-E_a$ = 9.01 kcal/mole, for isobutane; log $A_a/A_d$ = -5.70 mole/l and $E_e-E_a$= 11.0 kcal/mole. From the reported Arrhenius parameters for t-Butoxy radical decomposition reactions the parameters for t-Butoxy radical reactions with isobutane and cyclohexane are estimated to be log $A(l/mol{\cdot}sec)$ = 8.4, $E_a$ = 4.3 kcal/mol and $log A (l/mol{\cdot}sec)= 9.9,\;E_a$ = 6.3 kcal/mol, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.5
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• pp.451-458
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• 2002

Absorptive type SP3T(Single Pole Three Throw) and SP8T switch modules over the 6-18 GHz are designed and fabricated. The epitaxial structure of GaAs PIN diode for switch modules are designed for low loss and high power capability. The maximum input power of SP3T and SP8T switch modules are 2 W and 1 W, respectively. The switching time with driver circuit is less than 130 nsec. The maximum insertion loss of SP3T switch module and SP8T module shows 2.8 dB and 4.2 dB, respectively. The isolation between input port and output port is more than 55 dB. Two switch modules for electronic warfare system have passed the environment tests of the related test items.

• Kyungpook Mathematical Journal
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• v.61 no.3
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• pp.487-494
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• 2021

In this paper, we study rings with Noetherian spectrum, rings with locally Noetherian spectrum and rings with t-locally Noetherian spectrum in terms of the polynomial ring, the Serre's conjecture ring, the Nagata ring and the t-Nagata ring. In fact, we show that a commutative ring R with identity has Noetherian spectrum if and only if the Serre's conjecture ring R[X]_U has Noetherian spectrum, if and only if the Nagata ring R[X]_N has Noetherian spectrum. We also prove that an integral domain D has locally Noetherian spectrum if and only if the Nagata ring D[X]_N has locally Noetherian spectrum. Finally, we show that an integral domain D has t-locally Noetherian spectrum if and only if the polynomial ring D[X] has t-locally Noetherian spectrum, if and only if the t-Nagata ring $D[X]_{N_v}$ has (t-)locally Noetherian spectrum.

• Nuclear industry
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• v.29 no.7
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• pp.58-60
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• 2009

시험 검사 인증 기술 컨설팅 분야의 세계적인 서비스 기업인 T$\ddot{U}$V S$\ddot{U}$D 그룹의 한국 법인인 T$\ddot{U}$V S$\ddot{U}$D Korea가 최근 원자력 기기 및 시스템 설계 엔지니어링 기업인 (주)GNEC를 인수, 합병하면서 국내 원자력 시장에 성큼 진출하는 한편 우리나라 원자력사업의 해외 시장 진출을 적극적으로 도울 계획을 세우고 있다. 라이너 블록 사장은 GNEC 인수 후 기자회견을 통해 "원자력 기기 및 설계, 교육 및 엔지니어링 서비스 등 관련 기술 지원에 앞장서 국내 에너지 산업의 활성화에 앞장서는 것을 물론 국내 원자력 산업의 해외 진출을 지원하면서 중국, 인도 및 중국 등 아시아 시장에 적극 진출할 것" 이라고 말하고 "원전 관련 기술을 갖고 있는 다른 기업에 대해서도 향후 인수 합병(M&A)에 나설 계획"이라고 밝혔다. T$\ddot{U}$V S$\ddot{U}$D Korea가 GNEC 인수를 마무리한 시점인 지난 10월 19일, 한강이 내려다보이는 여의도 대한생명 63빌딩 12층 T$\ddot{U}$V S$\ddot{U}$D Korea 사장실에서 라이너 블록 사장을 만났다. 인터뷰 자리에는 이번 GNEC 합병에 큰 역할을 한 김두일 T$\ddot{U}$V S$\ddot{U}$D 고문이 배석하여 인터뷰를 도왔다.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.425-431
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• 2010

This study explored the effects and the effectiveness of the new method of 3D FIESTA by making quantitative comparison with the conventional 3D FSE method which is frequently employed on patients with sudden hearing loss in clinical settings. For this study, 3D FSE images acquired with 3.0T MR scanner and T2-weighted axial plane 3D FIESTA images were respectively taken from 40 patients diagnosed with Sensorineural Hearing Loss (SSHL). When obtaining those images, sagittal reconstructions oriented perpendicular to the nerve were performed in order to get sagittal images of both right and left internal auditory canal. The findings showed that both SNR and CNR were higher among the group to whom the 3D FIESTA method was applied than the group to whom the conventional 3D FSE method was applied.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.613-624
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• 2002

Electrical characteristics of two types of 20 GHz Push-Push GaAs MESFET dielectric resonator oscillators having Wilkinson and T-junction power combiners for the output stage have been investigated and compared. So we have explained that the output power and phase noise properties of the Push-push FET DRO are depending on return loss and isolation characteristics of power combiner at the fundamental and the second harmonic frequencies. A Push-push oscillator for suppressing the fundamental frequency of 10 GHz and enhancing the second harmonic of 20 GHz has been designed and fabricated in microstrip configuration on 20 mil thick RT-Duroid($\varepsilon$$_{r}$ = 2.52) Teflon substrate. Return loss and isolation characteristics of T-junction and Wilkinson have been measured at the fundamental frequency of 10.2 GHz and the second harmonic frequency of 20.5 GHz. At the fundamental frequency, -12 dB return loss and -3.7 dB isolation have been measured for the T-junction power combiner, and -14 dB return loss and -11 dB isolation fur the Wilkinson power combiner. At the second harmonic frequency, -10 dB return loss and -7.5 dB isolation have been obtained for the T-junction power combiner, and -23 dB return loss and -22 dB isolation for the Wilkinson power combiner. As a result, we have confirmed that the oscillator based on the Wilkinson power combiner with better retrun loss and isolation characteristics produces more output power and better phase noise characteristics..

• Korean Journal of Mathematics
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• v.20 no.2
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• pp.185-191
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• 2012

Let D be an integral domain and SF(D) be the set of star operations of finite type on D. We show that if ${\mid}SF(D){\mid}$ < ${\infty}$, then every maximal ideal of D is a $t$-ideal. We give an example of integrally closed quasi-local domains D in which the maximal ideal is divisorial (so a $t$-ideal) but ${\mid}SF(D){\mid}={\infty}$. We also study the integrally closed domains D with ${\mid}SF(D){\mid}{\leq}2$.

• Bulletin of the Korean Mathematical Society
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• v.61 no.1
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• pp.147-160
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• 2024

In this paper, we define two new classes of monomial ideals I_𝑙,d and J_k,d. When d ≥ 2k + 1 and 𝑙 ≤ d - k - 1, we give the exact formulas to compute the depth and Stanley depth of quotient rings S/I^t_𝑙,d for all t ≥ 1. When d = 2k = 2𝑙, we compute the depth and Stanley depth of quotient ring S/I_𝑙,d. When d ≥ 2k, we also compute the depth and Stanley depth of quotient ring S/J_k,d.