Warm plasma effects on electromagnetic ion cyclotron wave MeV electron interactions in the magnetosphere : EMIC WAVES AND MEV ELECTRONS

Silin, I.,Mann, I. R.,Sydora, R. D.,Summers, D.,Mace, R. L. American Geophysical Union 2011 Journal of geophysical research Vol.116 No.a5

Three-dimensional Measurements by Using Deflectometry and the Double Hilbert Transform

Silin Na,Younghun Yu,Sanghoon SHIN 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.3

An improved phase retrieval method based the Hilbert transform is introduced to quantitatively calculate the phase distribution from the distorted fringe pattern. Also phase measurement deflectomety is widely used in specular-type samples. The background noise or background should be suppressed prior to applying Hilbert transform. In this process, a method for suppressing the background noise the double Hilbert transform, fast, automated, which requires only one image, is presented. The method is easy to implement, and measurements can be conducted. We used the double Hilbert transform method to retrieve the phase and suppressed the background in computer simulations and experiments involving the phase measuring deflectometry method.

Deflectometric Measurement of a Fine Metal Mask by Using Near Infrared to Reduce Scattering

Silin Na,Sanghoon SHIN,Doocheol KIM,Younghun Yu 한국물리학회 2016 New Physics: Sae Mulli Vol.66 No.1

Deflectometry is a non-interferometric method that is easy to set up and can be easily applied to investigations of the flatness of plates. The samples need to have specular surfaces. However, every surface has roughness and is not perfectly specular. The specular reflection depends on the wavelength and the size of the scatterer on the surface. We investigated the scattering effect at different wavelengths and chose an appropriate wavelength of the light source for reducing the scattering effect. Fine metal masks (FMMs) are used in organic deposition processes and are required to be flat, even though most FMMs have partially specular surfaces. Experimentally, we used near infrared deflectometry to investigate the variations in the shapes of the surfaces of FMMs subjected to different stresses.

Effect of Partial Spatial Coherence on Image Sharpness

Silin NA,김두철,유영훈 한국물리학회 2019 New Physics: Sae Mulli Vol.69 No.12

Holographic displays are coherent light processing systems based on interference and diffraction, thus they generally use coherent light source. Highly coherent light makes some undesired effects, such as speckle noise. We studied how the degree of spatial coherence affected the image sharpness of a holographic display. We used rotating ground glass to control the degree of spatial coherence and a non-interferometric holographic system for imaging with simultaneous determination of the spatially coherent illumination. Image sharpness is related to both the temporal and the spatial coherence of the light source; our results demonstrate a direct relationship between spatial coherence and image sharpness

Digital Holographic Microscopy Using a Spherical Reference Wave and Polarization Hologram

Na Silin,Shin Sanghoon,Yu Younghun 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.10

A reflective lensless on-axis digital holographic microscopic system with a spherical reference wave was developed and used to obtain a reconstructed image at several magnification levels. A polarization image camera (PIC) was used to suppress the direct current term and twin images of the on-axis digital holography (DH) microscope. The PIC was used in a parallel phase-shifting DH system without mechanical movement. Here, we show that the magnification can be adjusted by changing the ratio of the distance between the object and the PIC to that between the reference light and the PIC while maintaing a constant reconstruction distance.

The evolution of microstructure and resistance in electroplated copper films by linear integrated laser scanning annealing

Lingyue Tan,Silin Han,Shuhui Chen,Tao Hang,Huiqin Ling,Yunwen Wu,Ming Li 대한금속·재료학회 2021 ELECTRONIC MATERIALS LETTERS Vol.17 No.2

Thermal treatment is an effective way to decrease the resistivity and internal stress by inducing grain growth accompaniedwith redistribution of embedded impurities. With the narrowing of Cu interconnects in IC packaging, the increased resistanceis becoming the main issue that hindering the electrical performance of IC. Herein, a laser annealing method by linerscanning (LALS) to anneal the Cu interconnects were reported which provide a gradient thermal field for the crystallographic/microstructure transition. The impacts of laser annealing on the sheet resistance of the electroplating Cu films wereinvestigated in aspects of microstructure and phase field simulation. Cu films treated by LALS owned larger average grainsize, better recrystallization fraction, and significantly higher average grain aspect ratio than conventional annealing, whichindicated the increased driving force for grain boundaries evolution by LALS method. This study exhibited the direct evidenceon the impacts of laser annealing process on the resistance of electroplated Cu films. The laser annealing process witha local temperature gradient caused a significant decline in Cu electrical resistance compared to the conventional annealingprocess, indicating its extraordinary potential in improving Cu wire conductivity. This work will provide a scientific basis forselecting the post-treatment process for electrodeposited Cu films to achieve ideal electrical properties and microstructurein electronics industry applications.

A Pulse Shape Discrimination Method with CsI Using the Ratio of Areas for Identifying Neutrons and Gamma Rays

우종관,고재원,Silin Na,김용주,이효상 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.5

Identification of gamma rays and neutrons is a fundamental technique used in elementary particle physics experiments, such as the search for dark matter, double beta decay, etc. The pulse shape discrimination (PSD) methods with liquid and crystal scintillators, a well-known technology, have been under development for several decades. The PSD methods with crystal scintillators are known to be less stable and less effective than PSD methods with liquid crystals. Here, an improved PSD technique with a CsI crystal scintillator based on the well-known PSD methods with liquid scintillators is introduced. In this study, we found the possibility that the proposed PSD with a CsI crystal scintillator provides a performance to discriminate gamma rays and neutrons equivalent to that of a PSD with a liquid scintillator.

Research on Dynamic Intelligent Information Processing Method for Distributed Generation Systems Based on Multi-Agent Techniques

Tieyan Zhang,Silin Wang,Meijun Li 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.8

Distributed renewable energy generation is lack of intelligent information processing and decision-making section. The above problems can be solved effectively by the means of intelligent information processing technology based on the dynamic structure of multi-agent for distributed renewable energy. In order to solve the problems of less data and poor information, this paper puts forward fuzzy hyperbolic model and attempts to use dynamic intelligent information processing technology based on multi-agent to change the unreliable, inaccurate information into be full, reliable and accurate. And then the information we have obtained could be intelligent fitted, filtered and decided. The self-organizing self-learning and reasoning ability of multi-agent are considered when the information processing. The intelligent information processing section is comprised of three layers and two kinds of agents. The two kinds of agents are Bus Agents and Coordination Agents, and the three structural layers are the data layer, the filter layer and the policy making layer. Moreover the information have been processed could be utilized.

Moving Object Detection with High Precision via Marked Watershed and Image Morphology

Qingqing Fu,Silin Xu,Aiping Wu 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.11

This paper presents a non-stationary object detection method by exploring time-varying spatial domain information in full motion video. Initially, the edge maps of difference image between two adjacent frames and current frame is generated via the well-known Canny edge detector. The distance of the edge pixels between the difference image and the current video frame are confined within a small value to determine the initial edge mask for the object in motion. The horizontal and vertical filling followed by morphological opening and closing operator are applied on the initial edge mask to create initial temporal segmentation mask of the moving object. The morphological dilation and corrosion operator are utilized to obtain binary marker image of the foreground and background which are used to modify the multi-scale morphological gradient image of current frame. Finally, the watershed algorithm is performed on the modified gradients to find the non-stationary objects accurately in the spatial domain of motion frames. Processed video results show detection accuracy of 98% and 99% for four different video experimentation test-beds involving fast and slow human motion. In this operation, the proposed technique eliminates the problem of over-segmentation of the watershed algorithm and extracts visually distinct, contextually meaningful non-stationary objects as they randomly appear (or disappear) in video sequences.

Hilbert 변환과 투과형 편향법을 이용한 3차원 측정연구

나실인,유영훈,Na, Silin,Yu, Younghun 한국광학회 2016 한국광학회지 Vol.27 No.2

광학 부품 표면의 3차원 측정을 위하여 투과형 편향법을 이용하였다. 한 장의 영상으로부터 변화된 위상을 추출하기 위하여 Hilbert 변환을 이용하였다. 편향법은 면적이 비교적 크고 거울과 같이 산란이 거의 없는 물체의 3차원 측정을 하는데 유용하다. 편향법을 통해 얻은 왜곡 무늬와 hilbert 변환한 영상을 이용하여 위상을 구했으며, 이로부터 파면의 기울기를 측정하고, 구한 기울기로부터 3차원 프로파일을 구하기 위해 최소자승법을 이용하였다. 전산기 시늉과 실험을 통해 Hilbert 변환을 이용한 3차원 측정법이 유용함을 확인하였다. We used transmission deflectometry to measure the three-dimensional shapes of optical components, and we used the Hilbert transform to retrieve the phases from measured deformed fringe images. Deflectometry is useful for measuring large-scale samples, and specular samples. We have retrieved the phases from deformed fringe images and Hilbert-transformed images, and have used the least-squares method to find the height information. We have verified that phase retrieval using Hilbert transform is useful by computer simulation and experiment.