• KIEAE Journal
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• v.11 no.2
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• pp.9-15
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• 2011

Many Korean palaces such as Deoksu Palace and Kyungbok Palace are located in downtown Seoul. Modern high-rise buildings around the palace have been the background scenery of traditional architecture in it. In this case, such landscapes mixed with traditional images and contemporary images can give a negative impression to visitors watching from inside the palace. In this study, we analysed the correlation between landscape image of Deoksu Palace and trees' view blockage of buildings around it with three independent variables. The first variable is completely blocked view of buildings around the palace by the trees. The second variable is half-blocked view of buildings around the palace by the trees. The third variable is the view of buildings around the palace that is not blocked by the trees. The analysis showed that there were some significant correlations between landscape image of Deoksu Palace and trees' view blockage of buildings around it. It also showed that the view blockage ratio by the trees has positive correlation with improvement of landscape image of the palace.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3664-3677
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• 2017

Abrupt scene changes generally incur the afterimage effect. So, the unblocked image portion is still viewed by human eyes just after it is blocked by some pattern. Yovo's secure display method utilized this phenomenon and it is systematically analyzed using computational afterimage modeling by replacing the complex afterimage effect via simple low-pass filtering. With this approach, realistic images perceived by the human eye can be computationally generated at every single moment, especially reflecting the afterimage effect. The generated images are compared with the original images to determine the factors that affect the image quality of the secure display method. The simulation results demonstrate that the ratio of the unblocked portion to the blocked portion of an image and the playback rate are two primary factors related to the recognized image quality. We also found that the two factors are still effective for generalized secure display techniques.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.173.2-173
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• 2001

In this paper, an Internet-based monitoring system is studied which analyzes visual image of drifted snow and measures the amount of snowing. The system is composed with reference ruler where LED's are attached, a camera, and PC with a controller. The length of the ruler is 1.5m and the interval of the LED's is 1cm. The controller synchronizes the on-off control of each LED with the image frame of the camera. When the snow is accumulated along the ruler, the corresponding LED is blocked and the lowest position of the lighted LED is estimated with this captured image of the camera. Because of week intensity of LED light and light rays of outdoors, it is hard to discriminate which LED is blocked due to snow. Image processing method is used to obtain proper resolution and good accuracy. This system ...

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.1
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• pp.39-47
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• 2001

A blocked zerotree coding algorithm for compression of subband image is proposed. Significance of blocks with respect to a certain threshold are coded with a set of transition rules for the significance of blocks. Significant blocks are quantized by vector quantization. The basic idea for this coding approach are: 1) Subband images are coded by blocks, 2) Important blocks based on the significance of blocks are coded and quantized, 3) Multiband codebook which is composed of sub-codebooks dedicated for each threshold and subband level is adapted to produce good reproduction vectors for vector quantization. The compression results are similar to Shapiro's zerotree coding even though ours are obtained without entropy coding of bit streams from blocked zerotree encoder. If an entropy coding is applied to the bitstream, PSNR will be improved.

• The KIPS Transactions:PartB
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• v.9B no.4
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• pp.471-480
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• 2002

In this paper, we implemented a real-time system improving the performance of the paper currency discrimination by integrating a weighted region of interest matching algorithm with a weighted shape feature matching algorithm of the blocked image. The system classifies the paper currency by comparing a query image with compared images based on the database that contain images of paper currency. Especially, the system has good efficiency at the contaminated, rotated, and translated paper currency. The system hardware consists of three parts as follows : the paper currency image acquired by CIS(contact image sensor) is applied to the pre-processing part with A/D converter and PLD. Finally the pre-processed image data are classified by the main image processing part with a high-speed DSP based on the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.1
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• pp.123-132
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• 1993

This paper presents the segmentation of sentence area and diagram area from docwnent image. For extracting the sentence area, we perform the Dilation, basic operation of Morphology, to the document image and obtain the smeared document image. After the smeared docwnent image is blocked, we determine the writing form by the vertical and horizontal characteristics of the document image and calculate the skew from it. And then, we relocate the document image and extract the chatacter string from the relocated docwnent. 11 document images of three classes are considered and the character string has been well extracting from 11 document images.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.124-127
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• 2002

Ceil embolisation technique has been used to treat the intracranial aneurysms. Microcoils inserted into the aneurysm sac induce the blood flow stagnation inside the aneurysm sac, which causes the thrombus formation and embolisation of aneurysm. Since the intraaneurysmal flow patterns affect the embolisation process, we want to measure the flow field for different locations of coil inside the aneurysm sac . Lateral aneurysm models are manufactured using rapid prototyping, and the velocity fields are measured using particle image velocitimeter. Distally blocked models showed less flow into the aneurysm sac comparing to proximally blocked models. Also blocking the neck of aneurysm showed better inflow blocking comparing to blocking the dome of aneurysm. These results suggest that distal neck should be the preferred locations of coil for aneurysm embolisation.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.4
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• pp.423-430
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• 2002

When JPEG, a standard of stopped image compression, is high compressed, the image is severely blocked. Since JPEG performs compression after taking DCT(Discrete Cosine Transform). It has a defect that the quality of image becomes low with aliasing in the case of high compression. Though transformation cipher method can have high compression rate, flame nay happen to quality of image by transformation and reverse transformation. In this paper, we use wavelet transform and fractal theory in order to solve these problems. After we apply these two methods to stopped image, we can get some good results, improvement of speed and compression rate, and elimination of blocking appearance. Besides, we show quality of restoration image is better than established one.

• Journal of Sensor Science and Technology
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• v.30 no.2
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• pp.76-81
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• 2021

In this study, we propose a machine vision system with a high object recognition rate. By utilizing a multiple-exposure image sensing technique, the proposed deep learning-based machine vision system can cover a wide light intensity range without further learning processes on the various light intensity range. If the proposed machine vision system fails to recognize object features, the system operates in a multiple-exposure sensing mode and detects the target object that is blocked in the near dark or bright region. Furthermore, short- and long-exposure images from the multiple-exposure sensing mode are synthesized to obtain accurate object feature information. That results in the generation of a wide dynamic range of image information. Even with the object recognition resources for the deep learning process with a light intensity range of only 23 dB, the prototype machine vision system with the multiple-exposure imaging method demonstrated an object recognition performance with a light intensity range of up to 96 dB.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.2
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• pp.119-129
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• 2024

Knowledge of the venous anatomy is essential for appropriately treating dural arteriovenous fistulas (AVFs). It is challenging to determine the overall venous structure despite performing selective angiography for dural AVFs with feeder from multiple selected arteries. This is because only a part of the veins can be observed through the shunt in the selected artery. Therefore, after performing selective angiography of all vessels to understand the approximate venous anatomy, the venous anatomy can be easily understood by closely examining the source image of computed tomographic angiography or magnetic resonance angiography. Through this, it is possible to specify the vein that is to be blocked (target embolization), thereby avoiding extensive blocking of the vein and avoiding various complications. In the case of dural AVF with feeder from single selected artery, if the multiplanar reconstruction image of the three-dimensional rotational computed tomography obtained by performing angiography is analyzed thoroughly, a shunted pouch can be identified. If embolization is performed by targeting this area, unnecessary sinus total packing can be avoided.