• Transactions of Materials Processing
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• v.19 no.7
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• pp.416-422
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• 2010

The $\{10\bar{1}2\}$ twinning characteristics, such as active twin variants, volume fraction of twins with strain, twin morphology, twin texture and angle relationship between twins, were dependent on the activation mode (i.e., tension parallel to the caxis or compression perpendicular to the c-axis). The selection criterion of active twin variants was governed by the Schmid law. This activation of selected twin variants depending on the activation mode consequently caused a totally different plastic deformation behavior in two activation modes. The differences in the deformation characteristics, such as flow stress and work hardening rate, between both activation modes were explained in relation with activation stresses for slips and twinning, relative activities of twinning and slips during plastic deformation, grain refining effect by twin boundaries (Hall-Petch effect), and twinning-induced change in activities of slips.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.734-748
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• 2023

A comprehensive investigation of the Ronen method is performed in homogeneous and heterogeneous slab problems from the Sood benchmark, considering isotropic and linearly-anisotropic problems. Three finite differences implementations are exercised and compared. The results are compared to reference solutions using one and two energy groups. The validation is performed for the criticality eigenvalue and the fundamental neutron flux distribution. The results demonstrate the significantly improved accuracy achievable by the Ronen method using a broad set of problems. For standard convergence tolerances, the maximal deviation in criticality eigenvalue is less than ten pcm, and the maximal deviation in the spatial distribution of the flux is less than 2%, always located near sharp interfaces or vacuum boundaries.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.81-89
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• 2009

To support dynamic Region-of-Interest(ROI) in JPEG2000, a fast ROI mask generation is needed. In the existing methods of ROI coding, after scanning all the pixels in order and discriminating ROI, an ROI mask has been generated. Our method scans 4 pixels of the corners in one code block, and then based on those informations, scans the edges from the corners to get the boundaries of ROI and background. These informations are consisted of a distributed information of ROI and two coordinates of the pixels, which are the points the edges and the boundaries meet. These informations are transmitted to encoder and supported for fast ROI mask generation. There were no great differences between the proposed method and the existing methods in quality, but the proposed method showed superiority in speed.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.2 s.35
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• pp.135-140
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• 2005

Although it was recently observed that severe fatigue damage was formed in Al or Cu interconnects due to the cyclic temperatures generated by Joule heating of the metal lines by the passage of alternating currents (AC), AC loading frequency effect on the damage evolution characteristics are not known so far. This work focused on the effect of AC loading frequency (100 Hz vs. 10 kHz) on the thermo-mechanical fatigue characteristics by using polycrystalline sputtered Cu lines with temperature cycles with amplitudes from 100 to $300^{\circ}C$. It was consistently observed that higher loading frequency accelerated damaged grain growth and led to earlier failure irrespective of Cu grain sizes. The frequency effect is believed to result from differences in the concentration of defects created by the deformation-induced motion of dislocations to the grain boundaries.

• Journal of the Korean Ceramic Society
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• v.30 no.12
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• pp.1066-1070
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• 1993

When looked upon as a polycrystalline, ceramics have two basic differences from a single crystal. One is that there exist grain boundaries, the other is that the crystal axes of each small crystal are arranged in random directions. But the crystal axes fo small crystals which compose ceramics may be made to have the tendency of being arranged in a specific direction. This is called that the crystal axes are oriented. The degree of the direction arrangement of the crystal axes is called orientation. In order to orient the crystal axes effectively, the fiberous barium titanates were made through KDC method and the ion exchange method. And then they were arranged through pressing, doctor blade, and syringe. As the result of Lotgering evaluation, the sample oriented through syringe showed the highest orientation. After sintering, though the most particles that had been fiberous shaped became global shape viewed through SEM, the orientation of the crystals was reinforced by means of sintering.

• Korean Journal of Remote Sensing
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• v.25 no.3
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• pp.287-294
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• 2009

KOMPSAT-2 like other high-resolution satellites has the time and angle difference in the acquisition of the panchromatic (PAN) and multispectral (MS) images because the imaging systems have the offset of the charge coupled device combination in the focal plane. Due to the differences, high altitude and moving objects, such as clouds, have a different position between the PAN and MS images. Therefore, a mis-registration between the PAN and MS images occurs when a registration algorithm extracted matching points from these cloud objects. To overcome this problem, we proposed a new registration method. The main idea is to discard the matching points extracted from cloud boundaries by using an automatic thresholding technique and a classification technique on a distance disparity map of the matching points. The experimental result demonstrates the accuracy of the proposed method at ground region around cloud objects is higher than a general method which does not consider cloud objects. To evaluate the proposed method, we use KOMPSAT-2 cloudy images.

• Korean Journal of Cognitive Science
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• v.18 no.4
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• pp.325-350
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• 2007

This study investigated global and local characteristics of eye movement while 16 college students read 48 easy Korean sentences. It was found that readers lusted for about 225ms at the word cluster(eojeol), made a forward saccade of about 3.6 characters to the next word, skipped short and high-frequent words about 25% during the first-pass reading, and regressed backward at 19%. There were also individual differences in readers' pattern of fixation and saccade. In addition, the effects of word cluster length and word frequency and the effects related to landing position were examined. The eyes landed on the center of a word cluster more frequently than on the boundaries. When the eyes landed at the boundaries, the eyes fixated the word cluster again more frequently. The word clusters with high-frequency words were read faster than those with low-frequency words.

• Journal of Korean Society of Rural Planning
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• v.25 no.3
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• pp.37-44
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• 2019

The value of Jeju Batdam has been reexamined as it is listed as a nationally important agricultural heritage and globally important agricultural heritage systems. However, it is already exposed to threats such as reduction of agricultural population and cultivation area. Despite efforts like the agricultural heritage system to preserve traditional agriculture, there is few basic investigation into the current status of Jeju Batdam. The purpose of this study is to estimate the length of Jeju Batdam. We used the continuous cadastral map of Jeju area to extract the boundaries of the field lot. In the cadastral map, the farmland was selected by selecting dry fields, paddy fields and orchards. 300 sample site were selected from the extracted farmland, and the boundaries between the Internet map and the parcels were superimposed and the differences were confirmed on the drawing. After that, field survey was conducted to confirm the boundary of the parcels and the existence of actual Batdam. It is estimated that the length estimated from this study is at least 23,983km and maximum 142,353km, which is at least 1,830km longer than 22,108km announced in 2007. Since Jeju Batdam is based on land parcel boundary, it is an objective and efficient method to utilize intellectual information. In addition, because it is subordinate to farmland, new information can be extracted reflecting the change of land use and make the spatial database based on the cadastral maps.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.169-179
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• 2013

Change detection algorithms take two image frames and return the locations of newly introduced objects which cause differences between the images. This paper presents a new change detection method, which classifies intensity changes due to introduced objects, reflected light and shadow from the objects to their neighborhood, and the noise, and exactly localizes the introduced objects. For classification and localization, first we analyze the histogram of the intensity difference between two images, and estimate multiple threshold values. Second we estimate candidate object boundaries using the gradient difference between two images. Using those threshold values and candidate object boundaries, we segment the frame difference image into multiple regions. Finally we classify whether each region belongs to the introduced objects or not using textures in the region. Experiments show that the proposed method exactly localizes the objects in various scenes with different lighting.

• The KIPS Transactions:PartB
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• v.15B no.5
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• pp.383-390
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• 2008

Block based transform coding is most popular approach for image and video compression. However it suffers from severe quality degradation especially from blocking artifacts. The subjective quality degradation caused by such blocking artifacts in general does not agree well with an objecive quality measurement such as PSNR. Hence new quality evaluation technique is necessary. We propose a new image quality assessment method by measuring blocking artifacts for block based transform coded images. In order to characterize blocking artifacts, proposed method utilizes the facts that, blocking artifacts, when occur, have different pixel values along the block boundaries and such differences usually continuously span along the whole boundaries. This method does not require the original uncompressed image. It operates on single block boundary and quantifies the amount of blocking artifacts on it. Experiments on various compressed images various bitrates show that proposed quantitative measure of blocking artifacts matches well with the subjective quality of them judged by human visual system.