• Title/Summary/Keyword: Multiple layers

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Rapid Thermal Annealing at the Temperature of 650℃ Ag Films on SiO2 Deposited STS Substrates

  • Kim, Moojin;Kim, Kyoung-Bo
    • Applied Science and Convergence Technology
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    • v.26 no.6
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    • pp.208-213
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    • 2017
  • Flexible opto-electronic devices are developed on the insulating layer deposited stainless steel (STS) substrates. The silicon dioxide ($SiO_2$) material as the diffusion barrier of Fe and Cr atoms in addition to the electrical insulation between the electronic device and STS is processed using the plasma enhanced chemical vapor deposition method. Noble silver (Ag) films of approximately 100 nm thickness have been formed on $SiO_2$ deposited STS substrates by E-beam evaporation technique. The films then were annealed at $650^{\circ}C$ for 20 min using the rapid thermal annealing (RTA) technique. It was investigated the variation of the surface morphology due to the interaction between Ag films and $SiO_2$ layers after the RTA treatment. The results showed the movement of Si atoms in silver film from $SiO_2$. In addition, the structural investigation of Ag annealed at $650^{\circ}C$ indicated that the Ag film has the material property of p-type semiconductor and the bandgap of approximately 1 eV. Also, the films annealed at $650^{\circ}C$ showed reflection with sinusoidal oscillations due to optical interference of multiple reflections originated from films and substrate surfaces. Such changes can be attributed to both formation of $SiO_2$ on Ag film surface and agglomeration of silver film between particles due to annealing.

Pharmacognostical Studies on Codonopsis lanceolata (더덕(사삼(沙蔘))의 생약학적 연구)

  • Kim, Chong-Hyun;Chung, Myung-Hyun
    • Korean Journal of Pharmacognosy
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    • v.6 no.1
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    • pp.43-47
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    • 1975
  • Attempts were made to determine the characteristics of the morphology of Codonopsis lanceolata $T_{RAUT's}$ root. Its saponin and crude powder were examined by foaming and hemolytic tests and by observing transverse sections: 1) The cork-layer was consisted of multiple cells, and some of the cork cells contained monoclinic prism crystals of calcium oxalates. 2) The vascular bundle was formed of radial arrangement by the preminentic bursting pith and the irregular cambium ring with the abnormal growth. 3) The latex vessel and latex of the cortex were brown-gray or yellowish-brown. The latex vessel and sieve tube were consisted of the independent aggregates which had a number of layers. It had much more independent aggregates than Platycodi Radix. 4) The xylem was less than the phloem portion. The thick-walled vessels which had one to five lines ware more distributed than in Platycodi Radix. 5) The inulin distribution on a piece of section which is dipped in alcohol was observed through out the tissues, but starch grain was not found in it. 6) The duration time of foaming reaction of the crude powder in test tubes was shorter than that of Platycodi Radix. Foaming index of the foaming test of five percent decoctions was 3.33, 7) In the hemolytic test which used 10 percent decoction and one percent saponin solution, hemolytic action was very weak.

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Estimation of Forest LAI in Close Canopy Situation Using Optical Remote Sensing Data

  • Lee, Kyu-Sung;Kim, Sun-Hwa;Park, Ji-Hoon;Kim, Tae-Geun;Park, Yun-Il;Woo, Chung-Sik
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.305-311
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    • 2006
  • Although there have been several attempts to estimate forest LAI using optical remote sensor data, there are still not enough evidences whether the NDVI is effective to estimate forest LAI, particularly in fully closed canopy situation. In this study, we have conducted a simple correlation analysis between LAI and spectral reflectance at two different settings: 1) laboratory spectral measurements on the multiple-layers of leaf samples and 2) Landsat ETM+ reflectance in the close canopy forest stands with fieldmeasured LAI. In both cases, the correlation coefficients between LAI and spectral reflectance were higher in short-wave infrared (SWIR) and visible wavelength regions. Although the near-IR reflectance showed positive correlations with LAI, the correlations strength is weaker than in SWIR and visible region. The higher correlations were found with the spectral reflectance data measured on the simulated vegetation samples than with the ETM+ reflectance on the actual forests. In addition, there was no significant correlation between the forest.LAI and NDVI, in particular when the LAI values were larger than three. The SWIR reflectance may be important factor to improve the potential of optical remote sensor data to estimate forest LAI in close canopy situation.

Signal integrity analysis of system interconnection module of high-density server supporting serial RapidIO

  • Kwon, Hyukje;Kwon, Wonok;Oh, Myeong-Hoon;Kim, Hagyoung
    • ETRI Journal
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    • v.41 no.5
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    • pp.670-683
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    • 2019
  • In this paper, we analyzed the signal integrity of a system interconnection module for a proposed high-density server. The proposed server integrates several components into a chassis. Therefore, the proposed server can access multiple computing resources. To support the system interconnection, among the highly integrated computing resources, the interconnection module, which is based on Serial RapidIO, has been newly adopted and supports a bandwidth of 800 Gbps while routing 160 differential signal traces. The module was designed for two different stack-up types on a printed circuit board. Each module was designed into 12- (version 1) and 14-layer (version 2) versions with thicknesses of 1.5T and 1.8T, respectively. Version 1 has a structure with two consecutive high-speed signal-layers in the middle of two power planes, whereas Version 2 has a single high-speed signal placed only in the space between two power planes. To analyze the signal integrity of the module, we probed the S-parameters, eye-diagrams, and crosstalk voltages. The results show that the high-speed signal integrity of Version 2 has a better quality than Version 1, even if the signal trace length is increased.

Fabrication of the ITO/Mesh-Ag/ITO Transparent Electrode using Ag Nano- Thin Layer with a Mesh Structure and Its Characterization (메쉬 구조의 Ag 나노박막을 이용한 ITO/Mesh-Ag/ITO 고전도성 투명전극 제조 및 특성 분석)

  • Lee, Dong Hyun;Cho, Eou Sik;Kwon, Sang Jik
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.4
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    • pp.100-104
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    • 2019
  • The 'ITO/Ag/ITO' multilayers as a highly conductive and transparent electrode, even with the optimum thickness conditions, the transmittances were much lower than those of a single ITO layer on some ranges of the visible wavelength. In order to improve the transmittance, Ag layer was formed with mesh structure. Where, the thickness of the Ag layer was about 10 nm and the space between the Ag lines was varied from 2.9 ㎛ to 19.6 ㎛ with the fixed Ag width of about 1.2 ㎛ in order to vary an open ratio of the Ag mesh structure. The transmittance and sheet resistance in the ITO/Mesh-Ag/ITO multilayer structure were analyzed depending on the open ratio. As a result, a trade off in the open ratio was necessary in order to obtain the transmittance as high as possible and the sheet resistance as possible low. By the open ratio of about 86%, in the ITO/Mesh-Ag/ITO multilayer structure, the transmittance was nearly same as the single ITO layer and the sheet resistance was about 62.3 Ω/.

Layer-wise hint-based training for knowledge transfer in a teacher-student framework

  • Bae, Ji-Hoon;Yim, Junho;Kim, Nae-Soo;Pyo, Cheol-Sig;Kim, Junmo
    • ETRI Journal
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    • v.41 no.2
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    • pp.242-253
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    • 2019
  • We devise a layer-wise hint training method to improve the existing hint-based knowledge distillation (KD) training approach, which is employed for knowledge transfer in a teacher-student framework using a residual network (ResNet). To achieve this objective, the proposed method first iteratively trains the student ResNet and incrementally employs hint-based information extracted from the pretrained teacher ResNet containing several hint and guided layers. Next, typical softening factor-based KD training is performed using the previously estimated hint-based information. We compare the recognition accuracy of the proposed approach with that of KD training without hints, hint-based KD training, and ResNet-based layer-wise pretraining using reliable datasets, including CIFAR-10, CIFAR-100, and MNIST. When using the selected multiple hint-based information items and their layer-wise transfer in the proposed method, the trained student ResNet more accurately reflects the pretrained teacher ResNet's rich information than the baseline training methods, for all the benchmark datasets we consider in this study.

Terahertz Nondestructive Time-of-flight Imaging with a Large Depth Range

  • Kim, Hwan Sik;Kim, Jangsun;Ahn, Yeong Hwan
    • Current Optics and Photonics
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    • v.6 no.6
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    • pp.619-626
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    • 2022
  • In this study, we develop a three-dimensional (3D) terahertz time-of-flight (THz-TOF) imaging technique with a large depth range, based on asynchronous optical sampling (ASOPS) methods. THz-TOF imaging with the ASOPS technique enables rapid scanning with a time-delay span of 10 ns. This means that a depth range of 1.5 m is possible in principle, whereas in practice it is limited by the focus depth determined by the optical geometry, such as the focal length of the scan lens. We characterize the spatial resolution of objects at different vertical positions with a focal length of 5 cm. The lateral resolution varies from 0.8-1.8 mm within the vertical range of 50 mm. We obtain THz-TOF images for samples with multiple reflection layers; the horizontal and vertical locations of the objects are successfully determined from the 2D cross-sectional images, or from reconstructed 3D images. For instance, we can identify metallic objects embedded in insulating enclosures having a vertical depth range greater than 30 mm. For feasible practical use, we employ the proposed technique to locate a metallic object within a thick chocolate bar, which is not accessible via conventional transmission geometry.

Optical properties of ZnS ceramics by hot press stack sintering process (고온 가압 적층 소결에 의한 황화아연 세라믹스의 광학성 특성)

  • Park, Buem-Keun;Paik, Jong-Hoo
    • Journal of Sensor Science and Technology
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    • v.30 no.3
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    • pp.148-153
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    • 2021
  • During the manufacture of a ZnS lens with excellent transmittance in the mid-infrared region (3-5 ㎛) by the hot-press process, a single-layer sintering method is used in which one lens is manufactured in one process. Additional research is required to improve this single-layer sintering method because of its low manufacturing efficiency. To solve this problem, the variation in optical properties of ZnS lenses with change in sintering temperature was investigated by introducing a Stack sintering method that can sinter multiple lenses simultaneously. A carbon paper was placed between the molded lenses and sintered into five layers. The average permeability of 67% at medium infrared wavelengths of 3-5 ㎛ was excellent under the following sintering conditions: pressure of 50 MPa and temperature of 850℃. This value is 1% less than the average permeability in the case of single-layer sintering of the ZnS lens. It was confirmed that the stack sintering method developed in this study can be used to manufacture a large number of lenses with excellent characteristics in a single process.

Automation in Site Planning of Apartment Complex - Through Rhino Grasshopper's Parametric Modeling and Optimization - (아파트 최적 배치 자동화 - Rhino Grasshopper를 활용한 parametric model의 최적화를 중심으로 -)

  • Sung, Woo-Jae;Jeong, Yo-Han
    • Journal of KIBIM
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    • v.10 no.3
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    • pp.22-32
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    • 2020
  • Apartment building site planning is one of time consuming and labor-intensive tasks in architectural design field, due to its complexity in zoning regulations, building codes, local restrictions, and site-specific conditions. In other words, the process can be seen as a very complicated mathematical function with layers of variables and parameters, which ironically can be automated using computational methods on parametric tools. In this paper, a practical method of automating site planning of an apartment complex has been proposed by utilizing parametric approaches in Rhino 3D and Grasshopper. Two primary parameters, building heights and positions, determine the efficacy of building layouts under all regulatory standards, thus testing out numerous combinations of the two will produce some successful layout alternatives. For this, equation solver has been used for iterating the parametric model to sort out meaningful results among others. It also has been proven that the proposed process significantly reduced the time in site planning down to less than an hour on most cases, and many successful alternatives could be obtained by using multiple computers. Post evaluation processes such as day light and view shed analysis helped sort out the best performing ones out of functioning alternatives.

Multichannel Convolution Neural Network Classification for the Detection of Histological Pattern in Prostate Biopsy Images

  • Bhattacharjee, Subrata;Prakash, Deekshitha;Kim, Cho-Hee;Choi, Heung-Kook
    • Journal of Korea Multimedia Society
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    • v.23 no.12
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    • pp.1486-1495
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    • 2020
  • The analysis of digital microscopy images plays a vital role in computer-aided diagnosis (CAD) and prognosis. The main purpose of this paper is to develop a machine learning technique to predict the histological grades in prostate biopsy. To perform a multiclass classification, an AI-based deep learning algorithm, a multichannel convolutional neural network (MCCNN) was developed by connecting layers with artificial neurons inspired by the human brain system. The histological grades that were used for the analysis are benign, grade 3, grade 4, and grade 5. The proposed approach aims to classify multiple patterns of images extracted from the whole slide image (WSI) of a prostate biopsy based on the Gleason grading system. The Multichannel Convolution Neural Network (MCCNN) model takes three input channels (Red, Green, and Blue) to extract the computational features from each channel and concatenate them for multiclass classification. Stain normalization was carried out for each histological grade to standardize the intensity and contrast level in the image. The proposed model has been trained, validated, and tested with the histopathological images and has achieved an average accuracy of 96.4%, 94.6%, and 95.1%, respectively.