• Title/Summary/Keyword: triplet

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Triplet Exciton Annihilation Process on Two Dimensional Lattice of Naphthalene Choleic Acid Creystals

  • 송추윤;박치헌;장현화;남규천;최용국;국성근
    • Bulletin of the Korean Chemical Society
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    • v.17 no.11
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    • pp.1000-1004
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    • 1996
  • A random walk simulation was used to determine the triplet exciton density and annihilation rate for a two dimensional lattice of naphthalene choleic acid with small amount of β-methylnaphthalene (BMN). The results demonstrate that energy transfer efficiency (α) increases as density increases and the annihilation begins to become significant at triplet exciton densities higher then 10-3/sites. Another simulation was carried out to determine annihilation rate and unimolecular decay rate in the absence of BMN. The results indicate that the annihilation rate is equal to the unimolecular decay rate at the density of 1.2×10-3/sites.

QSO Candidates in Leo Triplet Field

  • 신윤경;변용익
    • Bulletin of the Korean Space Science Society
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    • 2003.10a
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    • pp.86-86
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    • 2003
  • We present intermediate-band spectral energy distribution (SED) of QSO candidates in Leo Triplet field. Leo Triplet is composed of three galaxies, NGC3623, 3627, and 3628 which appear to interact with each other. Based on X -ray information, Arp et al. (2002) selected QSO candidates and suggested that the known QSOs and these candidates might belong to the triplet system in spite of their apparent high redshift. Our photometry is based on BATC survey data, which consist of hundreds of 15 intermediate-band images. In order to derive SED of high signal to noise ratio for every sources in the field, we have combined images of the same filter and matched the sources in the combined images. QSO candidates were identified based on the shape of derived SED curves. We compare our results with Arp et al. (2002)'s QSO candidates.

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Mass Distribution and Spray Characteristics to Liquid-Gas Line Selection of Unlike Triplet Impinging Injector (비동질 3중 충돌형 인젝터의 기체-액체 라인 선택에 따른 분무특성)

  • Lee, I.C.;Lee, C.J.;Koo, J.Y.
    • Journal of ILASS-Korea
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    • v.11 no.4
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    • pp.205-211
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    • 2006
  • Impinging angle, impinging distance, length eve. diameter and injection pressure of a triplet injector were tested to evaluate the spray characteristics injected by liquid/gas combinations. Two different kinds of unlike triplet sprays were produced by changing the gas and liquid feed lines. One was the G-L-G(Gas-Liquid-Gas) type, and the other was L-G-L(Liquid-Gas-Liquid) type. Spray angles were wider with the G-L-G type than with L-G-L type. Mass distributions in spray were obtained with a, mechanical patternator. Mass distributions were not circular but elliptical distributions. When the range of mechanical patternator to injector decreased, mass distributions were more concentrated in the center region.

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Study on the Video Stabilizer based on a Triplet CNN and Training Dataset Synthesis (Triplet CNN과 학습 데이터 합성 기반 비디오 안정화기 연구)

  • Yang, Byongho;Lee, Myeong-jin
    • Journal of Broadcast Engineering
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    • v.25 no.3
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    • pp.428-438
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    • 2020
  • The jitter in the digital videos lowers the visibility and degrades the efficiency of image processing and image compressing. In this paper, we propose a video stabilizer architecture based on triplet CNN and a method of synthesizing training datasets based on video synthesis. Compared with a conventional deep-learning video stabilization method, the proposed video stabilizer can reduce wobbling distortion.

Macroscopic Breakup Characteristics of Water Gel Simulants with Triplet Impinging Spray Jet (젤 모사 추진제 삼중 충돌 분사 제트의 거시적 분열 특성 연구)

  • Hwang, Tae-Jin;Lee, In-Chul;Koo, Ja-Ye
    • Journal of ILASS-Korea
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    • v.15 no.3
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    • pp.109-114
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    • 2010
  • The implementation of gelled propellants systems offers high performance, energy management of liquid propulsion, storability, and high density impulse of solid propulsion. The present study focused on the macroscopic spray characteristics of liquid sheets formed by triplet impinging jets of non-Newtonian liquids which are mixed by Carbopol 941 0.5%wt. The results are compared to experiments conducted on spray images which formed by triplet impinging jets concerning with airassist effect at center orifice. When gel propellants are injected by doublet impinging jets at low pressure and high pressure, closed rim pattern shape appeared by polymeric effect from molecular force and showed inactive atomization characteristics, because of extensional viscosity related by restriction of atomization process and breakup time delay of turbulence transition. As increasing mass flow rate of the air(increasing GAR), spray breakup level is also increased.

Barcode Pattern Image Watermark Using Triplet (트리플릿을 이용한 바코드 패턴 이미지 워터마크)

  • Park, Byung-Su;Chu, Hyung-Suk;An, Chong-Koo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.12
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    • pp.2330-2335
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    • 2008
  • In this paper, we proposed a robust watermark scheme for image based on the discrete wavelet transform. In the first, we use the triplet method for embedding and extraction of watermark. Triplet method uses relationship among the discrete wavelet coefficients at the same position in the three detail subband of image. In the second, we use barcode Pattern Image for watermark scheme. By using barcode Pattern Images, a user is able to make many kinds of own watermark. In the third, the proposed method for image watermark provides the invisiblility which the other user can not discriminate watermark from watermarked image. The advantage of the proposed method is visibility when we extracted watermark from the image. The corresponding experimental results show that the proposed method has performance of a robustness from the noise attack.

Nanosecond Laser Flash Photolysis Study of 5-Styryl-1,3-dimethyluracil

  • Shim Sang Chul;Shin Eun Ju;Chae Kyu Ho
    • Bulletin of the Korean Chemical Society
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    • v.6 no.4
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    • pp.234-238
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    • 1985
  • The photoisomerization of 5-styryl-1,3-dimethyluracil is studied with nanosecond laser flash photolysis technique at room temperature. The laser flash photolysis of E-isomer produces the transient absorption spectrum regarded as the triplet-triplet absorption, but the transient absorption of Z-isomer does not show the typical decay curve, probably due to the facile photocyclization reaction during the laser flash photolysis. Using the energy transfer method on nanosecond laser spectroscopy, the energy of the lowest triplet state for E isomer is estimated to lie between 41.8 and 47 kcal/mol. The triplet lifetime for E-isomer obtained from the decay curve of the transient absorption is ca. 93ns. The $S_1 → T_1$ intersystem crossing of E-isomer on direct excitation is relatively inefficient at room temperature supporting the singlet mechanism for direct photoisomerization.

Triplet Class-Wise Difficulty-Based Loss for Long Tail Classification

  • Yaw Darkwah Jnr.;Dae-Ki Kang
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.3
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    • pp.66-72
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    • 2023
  • Little attention appears to have been paid to the relevance of learning a good representation function in solving long tail tasks. Therefore, we propose a new loss function to ensure a good representation is learnt while learning to classify. We call this loss function Triplet Class-Wise Difficulty-Based (TriCDB-CE) Loss. It is a combination of the Triplet Loss and Class-wise Difficulty-Based Cross-Entropy (CDB-CE) Loss. We prove its effectiveness empirically by performing experiments on three benchmark datasets. We find improvement in accuracy after comparing with some baseline methods. For instance, in the CIFAR-10-LT, 7 percentage points (pp) increase relative to the CDB-CE Loss was recorded. There is more room for improvement on Places-LT.

Miniature J-T Refrigerator Using Triplet Heat Exchanger (Triplet 열교환기를 사용하는 소형 J-T 냉동기)

  • Hwang, G.;Jeong, S.
    • Progress in Superconductivity and Cryogenics
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    • v.11 no.1
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    • pp.60-63
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    • 2009
  • Most J-T (Joule-Thomson) refrigerators use a Giaque-Hampson type heat exchanger due to its excellent thermal performance and compactness. The cryoprobe (cryosurgical probe) treating prostate cancer usually has a dimension of 17 gauge (1.6 mm diameter), so it does not have enough space to bear a Giaque-Hampson type heat exchanger. In this paper, the triplet heat exchanger is adopted as the heat exchanger of cryoprobe, and the performance is investigated with an experimental test. The result shows that the triplet heat exchanger can be substituted for Giaque-Hampson type heat exchanger in the application of cryosurgery.