• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.784-793
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• 2016

We present a single shot low coherence white light Hilbert phase microscopy (WL-HPM) for quantitative phase imaging of Si optoelectronic devices, i.e., Si integrated circuits (Si-ICs) and Si solar cells. White light interferograms were recorded by a color CCD camera and the interferogram is decomposed into the three colors red, green and blue. Spatial carrier frequency of the WL interferogram was increased sufficiently by means of introducing a tilt in the interferometer. Hilbert transform fringe analysis was used to reconstruct the phase map for red, green and blue colors from the single interferogram. 3D step height map of Si-ICs and Si solar cells was reconstructed at multiple wavelengths from a single interferogram. Experimental results were compared with Atomic Force Microscopy and they were found to be close to each other. The present technique is non-contact, full-field and fast for the determination of surface roughness variation and morphological features of the objects at multiple wavelengths.

• Journal of Soil and Groundwater Environment
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• v.19 no.6
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• pp.1-5
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• 2014

The following research was initiated in order to compare the relationship between the amount of gunfire shot and its resulting heavy metal pollution rate. The research was conducted at two firing ranges located inside a military unit stationed in the rear strategical area, where one full distance firing range is used by soldiers in active service, and the other is used by recruits and reserves. The heavy metal pollution rate was measured also on water sample collected from the target zone while raining. Based on values such as the real amount of gunshot fired, amount of heavy metal in the soil of the target zone, and the degree of heavy metal pollution for each firing range, the research showed that although pollution rate was higher when more gunshots were fired, there was no close correlation between the two. The water samples showed that this might result from the soils containing heavy metals eroded and transported by rain due to the target zone having no vegetation.

• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.983-991
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• 2019

This study aims to analyze movies which contain various stories according to the size of their shots. To achieve this, it is needed to classify dataset according to the shot size, such as extreme close-up shots, close-up shots, medium shots, full shots, and long shots. However, a typical video storytelling is mainly composed of close-up shots, medium shots, full shots, and long shots, it is not an easy task to construct an appropriate dataset for extreme close-up shots. To solve this, we propose an image cropping method based on the region of interest (ROI) detection. In this paper, we use the face detection and saliency detection to estimate the ROI. By cropping the ROI of close-up images, we generate extreme close-up images. The dataset which is enriched by proposed method is utilized to construct a model for classifying shots based on its size. The study can help to analyze the emotional changes of characters in video stories and to predict how the composition of the story changes over time. If AI is used more actively in the future in entertainment fields, it is expected to affect the automatic adjustment and creation of characters, dialogue, and image editing.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.5
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• pp.299-306
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• 2015

A conventional phased array system can control an ultrasonic beam electronically by adjusting the excitation time delay of individual elements in a multi-element probe and produce an ultrasonic image. In Contrast, full matrix capture (FMC) is a data acquisition process that allows receiving ultrasonic signals from one single shot of the phased array transducer element through all the other elements and captures the complete dataset from every possible transmit-receive combination. This FMC data can be used to create the ultrasonic image in post processing. It is possible to produce not only images equivalent to conventional phased array image but also total focusing method (TFM) images with improved resolution and sharpness, which is virtually focused at any point in a region of interest. In this paper, the system that can perform FMC by using a conventional phased array instrument is developed, and a study was conducted on the imaging algorithms to reconstruct sector B-scan and TFM images from FMC dataset.

• Journal of Powder Materials
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• v.22 no.1
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• pp.1-5
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• 2015

Powder injection molding is an important manufacturing technology to mass produce superalloy components with complex shape. Injection molding step is particularly important for realizing a desired shape, which requires much time and efforts finding the optimum process condition. Therefore computer aided engineering can be very useful to find proper injection molding conditions. In this study, we have conducted a finite element method based simulation for the spiral mold test of superalloy feedstock and compared the results with experimental ones. Sensitivity analysis with both of simulation and experiment reveals that the melt temperature of superalloy feedstock is the most important factor for the full filling of mold cavity. The FEM based simulation matches well the experimental results. This study contributes to the optimization of superalloy powder injection molding process.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.71-78
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• 1999

The application range of injection molded parts is expanding by the development of engineering plastics with good mechanical properties. Plastic gears are specially used as automotive parts due to an excellent performance in the characteristics of a strength vs. weight, and the study of injection molding process of plastic gear using Nylon66 is performed in this study. Filling, packing and cooling analyses were done by using the simulation software like Moldflow, and a mold was designed by following the simulation results. Pin-point gates with three points were taken to satisfy the design guides like a full-shot, and lower clamping force and uniform shrinkage. Characteristics of shrinkage of molded gear and temperature difference between cavity and core sides of a mold were shown.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.221-221
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• 2004

플라스틱의 사출성형중 용용 수지에 가스를 주입하는 가스사출성형(Gas Assisted Injection Molding GAIM)에 의해 성형품을 만드는 생산방법은 약 30년 전부터 유럽지역을 중심으로 시작되었다 GAIN의 개발 배경은 발포성형을 대체하기 위한 공법으로 개발되었다. 발포성형은 싱크마크(sink mark) 제거, 치수안정성, 강도보강의 목적으로 사용하는 공법이지만, 가스기포가 표면으로 빠져나오고 표면에 가스 기포가 발생하여 외관부품에 부적당하며, 두께가 5-6mm이하의 성형품에는 적용할 수 없고, 성형시간이 긴 문제점을 가지고 있어 이러한 문제를 보강한 공법을 연구할 결과로 GAIM이 탄생하게 되었다.(중략)

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.193-195
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• 2005

본 논문은 온톨로지를 이용하여 뉴스 비디오를 분야별로 자동으로 분류하는 효율적인 기법을 제안한다. 이를 위해서 뉴스 비디오를 파싱하여 키프레임(Key frame), 샷(Shot), 씬(Scene)으로 나누고 키프레임과 샷에서 특징 정보를 추출한다. 추출된 특징 정보를 이용하여 샷의 키워드 집합을 만들고 이를 이용하여 씬의 키워드 집합을 만든다. 그리고 씬의 키워드 집합을 어휘 온톨로지와 뉴스 온톨로지에 매칭(추론)하여, 씬의 분야를 결정한다. 또한 이렇게 결정된 분야를 기반으로 서로 유사한 씬들을 자동으로 그룹화하는 방법을 제안한다.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.973-979
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• 1995

The input equivalent noise charge (ENC) of hydrogenated amorphous silicon radiation detector diodes was measured and analyzed. The noise sources of amorphous silicon diodes were analyzed into three sources; shot noise, flicker noise and thermal noise from the contact resistance. By comparing the measured ENC with the calculated signal charge in uniform generation case, the signal-to-noise ratio (S/N) for the sample diodes is estimated as a function of the detector bias and the shaping time of Gaussian pulse shaper. The maximum S/N occurred at the bias level just above the full depletion voltage for shaping time of 2∼3 ${\mu}$sec. The developed method is useful in optimum design or amorphous silicon p-i-n diodes for charged particulate radiation spectroscopy.

• Korea Science and Art Forum
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• v.24
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• pp.375-388
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• 2016

Integrated analysis of OST and VST of animation Alladin is carried out in this study. The OST is classified into 4 stages (Introduction, Bridge Passage, Climax, and Ending) and their OST and VST characteristics are found for each step. Especially, high dynamic characteristics of OST elements (sound, tonality, tempo, major range, intensity, and instrumentation) and VST elements (image structure, camera shot, camera movement) are found in the Climax stage. Full Shot is highly used up to 47.9% and this helps to show that the two characters become one in the completion stage of love. This is common factor shown in the previous analysis of OST "Beauty and the Beast". It is also found that specific musical instruments are matched to specific characters in "Beauty and the Beast" and high/low position or up/down movement of the object in the screen are matched to specific musical instruments in 'Alladin'.