• Journal of Information Processing Systems
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• 제12권4호
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• pp.765-778
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• 2016

In watermarking schemes, the discrete wavelet transform (DWT) is broadly used because its frequency component separation is very useful. Moreover, LU decomposition has little influence on the visual quality of the watermark. Hence, in this paper, a novel blind watermark algorithm is presented based on LU transform and DWT for the copyright protection of digital images. In this algorithm, the color host image is first performed with DWT. Then, the horizontal and vertical diagonal high frequency components are extracted from the wavelet domain, and the sub-images are divided into $4{\times}4$ non-overlapping image blocks. Next, each sub-block is performed with LU decomposition. Finally, the color image watermark is transformed by Arnold permutation, and then it is inserted into the upper triangular matrix. The experimental results imply that this algorithm has good features of invisibility and it is robust against different attacks to a certain degree, such as contrast adjustment, JPEG compression, salt and pepper noise, cropping, and Gaussian noise.

• 대한기계학회논문집
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• 제16권10호
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• pp.1915-1927
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• 1992

본 연구에서는 3차원 압축성 내부유동해석 코드를 개발하여 터어빈 정익이나 동익 내부의 차원 익렬 유동을 수치적으로 해석하고자 한다. 여기에서 사용된 코드 는 Obyashi의 LU-ADI기법을 이용한 기존의 2차원 익렬 유동해석 코드를 3차원 유동장 으로 학장한 것이고, 난류유동해석에는, Baldwin-Lomax의 박층 대수모델을 3차원으로 확장한 알고리즘을 적용하였다.Kiock등이 실험한 선형 터어빈 익렬 내부의 천음속 유동장에 적용하여 양끝 벽면에 의한 3차원 유동장 특성을 분석하고, 3차원 익렬 유동 코드의 적합성을 검토하였다.

• BMB Reports
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• 제46권10호
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• pp.490-494
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• 2013

The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor-suppressing lipid phosphatase that is frequently absent in breast tumors. Thus, the stability of PTEN is essential for tumor prevention and therapy. The ubiquitin-proteasome pathway has an important role in regulating the functions of PTEN. Specifically, carboxyl terminus Hsp70-interacting protein (CHIP), the E3 ubiquitin ligase of PTEN, can regulate PTEN levels. In this study, we report that BCL-2-associated athanogene 5 (BAG5), a known inhibitor of CHIP activity, reduces the degradation of PTEN and maintains its levels via an ubiquitylation-dependent pathway. BAG5 is identified as an antagonist of cell tumorigenicity.

• 대한수학회보
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• 제55권5호
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• pp.1483-1490
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• 2018

In this note, it is proven that the slice Bergman kernels for some axially symmetric slice domains are zero-free by a simple method.

• 대한방사성의약품학회지
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• 제3권2호
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• pp.59-64
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• 2017

It has been reported that $^{64}Cu$ was radiolabeled with bombesin (BBN) peptide binding to the gastrin releasing peptide receptor expressed in human prostate cancer cells (PC3), confirming tumor target efficacy in mouse model. In this study, we developed the kit for the diagnosis and treatment of prostate cancer that can be used clinically using bombesin peptide available of $^{64}Cu$ and $^{177}Lu$ radioisotope labeling. The NODAGA-galacto-BBN peptide containing the NODAGA chelator and galactose was dispensed into a sterilized glass vial and lyophilized to prepare a kit. The stability of the kit after long-term storage in the $4^{\circ}C$ cold chamber and the radiolabeling efficiency after $^{64}Cu$ or $^{177}Lu$ labeling were confirmed by thin layer chromatography. When labeling with $^{64}Cu$ at the initial stage of storage, labeling efficiency of NODAGA-galacto-BBN peptide kit was over 96%, labeling efficiency was over 90% when $^{177}Lu$ was labeled. At 11 months after storage, the radiolabeling efficiency of kit against $^{64}Cu$ and $^{177}Lu$ was each over 95% and 90%. The cell viability was significantly reduced in the $^{177}Lu$-NODAGA-galacto-BBN treated group compared with the control and $^{177}Lu$ alone treated group in clonogenic assay. In conclusion, the NODAGA-galacto-BBN kit prepared by the lyophilization showed high stability over time and high yield of radioisotope labeling. Also $^{177}Lu$-NODAGA-galacto-BBN confirmed high cytotoxicity to prostate cancer cells. Therefore, the NODAGA-galacto-bombesin kit is expected to be useful for the diagnosis and treatment of prostate cancer patients.

• 환경위생공학
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• 제15권1호
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• pp.25-33
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• 2000

1%, 2%, 10%, 및 20%의 가교도를 갖는 클로로메틸화된 1,4-divinyl benzene에 1-aza-15-crown-5 거대고리 ligand를 치환반응으로 결합시키고, 이들 수지로부터 흡착에 미치는 pH, 시간, 수지의 가교도 그리고 용매의 유전상수 크기에 따른 흡착특성을 조사하였다. 금속이온들은 pH 4 이상에서 우라늄과 칼슘 이온들은 루테튬 이온보다 큰 흡착률을 보였으며, 금속이온들의 흡착 평형시간은 약 2 시간이었다. 한편, ethanol 매질에서의 흡착선택성은 $UO_2^{2+}>Ca^{2}>Lu^{3+}$ 이었고, 흡착력은 1%, 2%, 10%, 20%의 가교도 순 이었으며, 용매의 유전상수(물 : 78.54, 메탄올 : 32.63, 에탄올 : 24.30) 크기에 반비례하였다. 컬럼에서 1%의 가교도를 가진 수지와 금속이온들을 흡착시킨 후 용리액으로 pH2.5 $HNO_3$을 사용하여 각각 분리할 수 있었다.

• 한국재료학회지
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• 제28권6호
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• pp.355-360
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• 2018

$LuNbO_4:0.2Yb^{3+},xTm^{3+}$ powders were prepared using a solid-state reaction process. The effects of the amount of Tm on up-conversion(UC) and down-conversion(DC) luminescence properties are investigated. X-ray diffraction patterns confirm that $Yb^{3+}$ and $Tm^{3+}$ ions are successfully incorporated into Lu sites. Under 980 nm excitation, the UC spectra of the powders predominantly exhibit strong near-infrared emission bands that peak at 805 nm, whereas weak 480 nm emission bands are observed as well. The emission bands are assigned to the $^1G_4{\rightarrow}^3H_6$ (480 nm) and 3 $^3H_4{\rightarrow}^3H_6$ (805 nm) transitions of the $Tm^{3+}$ ions via an energy transfer from $Yb^{3+}$ to $Tm^{3+}$; two- and three-photon UC processes are responsible for the 805 and 480 nm emissions, respectively. The DC emission spectra exhibit blue emission ($^1D_2{\rightarrow}^3F_4$) of $Tm^{3+}$ at 458 nm. The amount of Tm affects the emission intensity with the strongest emissions at x = 0.007 and 0.02 for the UC and DC luminescence, respectively. The results demonstrate that $LuNbO_4:Yb^{3+},Tm^{3+}$ phosphors are suitable for bio-applications.

• 한국음향학회지
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• 제38권6호
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• pp.670-677
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• 2019

음성 또는 음향 이벤트 신호에서 발생하는 배경 잡음은 인식기의 성능을 저하시키는 원인이 되며, 잡음에 강인한 특징을 찾는데 많은 노력을 필요로 한다. 본 논문에서는 딥러닝을 기반으로 다중작업 오토인코더(Multi-Task AutoEncoder, MTAE) 와 와설스타인식 생성적 적대 신경망(Wasserstein GAN, WGAN)의 장점을 결합하여, 잡음이 섞인 음향신호에서 잡음과 음성신호를 추정하는 네트워크를 제안한다. 본 논문에서 제안하는 MTAE-WGAN는 구조는 구배 페널티(Gradient Penalty) 및 누설 Leaky Rectified Linear Unit (LReLU) 모수 Parametric ReLU (PReLU)를 활용한 변수 초기화 작업을 통해 음성과 잡음 성분을 추정한다. 직교 구배 페널티와 파라미터 초기화 방법이 적용된 MTAE-WGAN 구조를 통해 잡음에 강인한 음성특징 생성 및 기존 방법 대비 음소 오인식률(Phoneme Error Rate, PER)이 크게 감소하는 성능을 보여준다.

• 대한한의학방제학회지
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• 제27권1호
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• pp.73-86
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• 2019

Objectives : In spite of the difficulty of getting Agarwood, the number of species of wild Agarwood is rapidly decreasing by insistent demands. Here, we investigate how various formula of Agarwood is used so that we can make use of them more helpful in clinics today. Methods : Determining the range of 'the Sovereign and Minister' component more than 12.96%" or 'equally used', this study distinguished whether Agarwood is used as 'the Sovereign and Minister' component among 409 Agarwood formulas in "Sheng ji zong lu(聖濟總錄)" and 103 Agarwood formulas in "Donguibogam (東醫寶鑑)". Additionally, we analyzed the component ratio of Agarwood, and also the usage in Deficiency-Excess pattern. Results : Among Agarwood formulas in "Sheng ji zong lu" and "Donguibogam", each percentage of Agarwood formulas which Agarwood comprises 'the Sovereign and Minister' component was 26%(106/406) and 13%(13/99). Analyzing these formulas of "Sheng ji zong lu", 53 formulas were used in Deficiency pattern and other 53 formulas were used in Excess pattern. Also in "Donguibogam", 6 formulas were used in each Deficiency pattern and Excess pattern, and only 1 formula in both of Deficiency and Excess pattern. Conclusions : Showing almost equal ratio of usage in Deficiency-Excess pattern, this study showed that those Agarwood formulas of "Sheng ji zong lu" and "Donguibogam" which Agarwood comprises 'the Sovereign and Minister' component can be used in both Deficiency-Excess pattern evenly.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4642-4646
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• 2023

The Tb³⁺ or Eu³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor were fabricated by funace at 1500 ℃ for 12 h using a solid state reaction. The XRD (X-ray diffraction_Panalytical X'Pert Pro) and FE-SEM (field emission scanning electron microscope) are measured to confirm the crystalline structure and surface morphology of the phosphor. The Tb³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor emits the lights in 470~650 nm wavelength range due to transitions from ⁵D₄ to ⁷F_j. Therefore, it shows the green region in the CIE chromaticity diagram under both UV and X-rays excitations. The Eu³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor emits the lights in 550~750 nm wavelength range because of ⁵D_i to ⁷F_j. The emission is confirmed to be in the red region using the CIE chromaticity diagram. The Tb³⁺ or Eu³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor shows the characteristic f-f transition with a long decay time, which is about several milliseconds. They have the high efficiency of light emission for X-ray because of their high effective Z number (Z_eff = 58.5) and density. Therefore, they are very much promising phosphors for X-ray imaging application in medical fields.