• 지반과기술
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• v.4 no.3
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• pp.50-60
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• 2007

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.16-22
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• 2009

In this paper, we propose an auto gain/offset which considers the visibility of human visual system (HVS) and the histogram of a target image jointly. In the proposed method, the lower and upper clipping thresholds are determined to maximize the averaged visibility of the contrast-stretched image. The target image is then contrast-stitched by the gain and offset derived from the clipping thresholds. We define the visibility as a quantity related to the spatial JND, which means the threshold below which any change of a pixel from its textured neighbors is not recognized by the HVS. Experimental results show that the contrast-stretched images by the proposed method have better global and local contrasts compared to the results by some conventional methods.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.17-23
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• 2016

In the future network such as Internet of Things (IoT), the number of computing devices are expected to grow exponentially, and each of the things communicates with the others and acquires information by itself. Due to the growing interest in IoT applications, the broadcasting in Opportunistic ad-hoc networks such as Machine-to-Machine (M2M) is very important transmission strategy which allows fast data dissemination. In distributed networks for IoT, the energy efficiency of the nodes is a key factor in the network performance. In this paper, we propose a fuzzy logic based probabilistic multi-hop broadcast (FPMCAST) algorithm which statistically disseminates data accordingly to the remaining energy rate, the replication density rate of sending node, and the distance rate between sending and receiving nodes. In proposed FPMCAST, the inference engine is based the fuzzy rule base which is consists of 27 if-then rules. It maps input and output parameters to membership functions of input and output. The output of fuzzy system defines the fuzzy sets for rebroadcasting probability, and defuzzification is used to extract a numeric result from the fuzzy set. Here Center of Gravity (COG) method is used to defuzzify the fuzzy set. Then, the performance of FPMCAST is evaluated through a simulation study. From the simulation, we demonstrate that the proposed FPMCAST algorithm significantly outperforms flooding and gossiping algorithms. Specially, the FPMCAST algorithm has longer network lifetime because the residual energy of each node consumes evenly.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.1
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• pp.1-6
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• 2008

A flow visualization is conducted to investigate a flight characteristics of a Coleoptera and an effect of flapping elytra was considered in this study. Also the movements of outer wing(elytra) and inner wing is analyzed using High Speed Camera. As a result of this experiment, in case of flapping insect, three mechanisms to generate lift is confirmed. A small movement of outer wing(elytra) is confirmed and the effect of outer wing(elytra) is estimated.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.619-628
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• 2003

In this paper, an effective watermark detection technique in the wavelet transform domain is proposed. In this proposed method, the image is 2-level wavelet transformed, and then the watermark with a binary logo is embedded into middle band except baseband and high band to consider Invisibility and robustness. In this paper, we use an asymmetric thresholds watermarking (ATW) in which detection threshold is higher than inserting threshold in order to enhance watermark detection ratio in attacked images. In watermark detection phase, the detection value is not changed when the difference of the selected wavelet neighboring coefficient pairs Is smaller than specific value. The experimental results show that the proposed method has good quality and is robust to various attacks such as the JPEG lossy compression, noise addition, cropping, blurring, etc.

• Journal of Veterinary Clinics
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• v.27 no.3
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• pp.216-219
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• 2010

The purpose of this study is to establish experimental canine skin barrier disruption model, the study was designed to observe calcium ion in skin frozen tissue of canine skin and also the modulation of calcium ion distribution of normal skin with disrupted skin such as clipping, acetone, tape stripping damages according to time. To compare the changes of calcium ion gradient after damages, the distribution of calcium ion in the canine epidermis was visualized by blotting to gel containing chemical indicator (Calcium Green-1) with fluorescent microscope and the effects of skin barrier damages were examined according to time. Three mins and 1hr after acetone damage, the gradations of epidermis and hair follicle showed more radiant and disappeared after 48 hrs. On the contrary, 3mins and 1hr after tape stripping damage, the gradations showed more radiant than those of acetone damage, and these gradations were stabilized after 48 hrs. The method we presented here could show the visual image of the calcium ions in frozen tissue without further preparation, and it might be useful to investigate the role of calcium ion in the canine epidermal barrier recovery, however, it might be need further methodological improvement to get accurate quantitative information.