• Journal of Korean Society for Atmospheric Environment
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• v.18 no.4
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• pp.253-264
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• 2002

Surface ozone concentrations measured at 40 monitoring sites in three major cities (Seoul, Busan, and Daegu) of Korea during 1993~2000 were analyzed to understand the characteristics of temporal and spatial distributions. Trends were analyzed for annual mean, 95th percentiles of daily 8-hour maximum and days exceeding 8-h ozone standard of 60 ppb. Three indicators exhibited increasing trends (+0.75 ppb yr$^{-1}$ , +2.20 ppb yr$_{-1}$ , and +5.35 days yr$_{-1}$ on average) throughout the study period at all cities. Diurnal and seasonal variations were the largest in Seoul followed by Daegue and Busan, due to the high photochemical production and titration of ozone (Seoul), strong wind and constant supply of background ozone from the ocean (Busan). In the urban centers and industrial areas at all cities, scavenging of ozone by NO reduces the daily 8-hour maximum ozone by 10 ppb on average. High concentrations of ozone have frequently occurred in downwind eastern (Seoul and Daegu) or northern (Busan) sides of the territory. In particular, the coastal area of Busan had relatively high ozone level due to the local sea land breeze circulation. The results indicated that the temporal and spatial variations of ozone concentration were non -uniform and were closely related to the local environments; emission levels, climates, and geographic locations.

• Journal of Trauma and Injury
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• v.20 no.2
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• pp.119-124
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• 2007

Purpose: Management of the soft tissue defect in the lower extremity caused by trauma has always been difficult. Coverage with local and free muscle flaps after complete surgical excision of necrotic soft tissue and bone is a major strategy for treatment. There is no doubt that muscle provides a good blood supply, thus improving bone healing and increasing resistance to bacterial inoculation. However, accompanying problems are seen in cases with shallow dead space. This research was conducted to assess the efficacy of raising anterolateral thigh flaps and transferring them to the defect after complete debridement of non-viable, infected, and scar tissue as an alternative way to use local or free muscle flaps. Methods: From March 2005 to October 2007, 18 cases of soft tissue defect on lower extremities were re-surfaced with an anterolateral thigh perforator free flap. Results: The follow-up period ranged from 1 to 31 months with a mean of 15.9 months. All flaps survived completely. Satisfactory aesthetic and functional results were achieved. Under a two-point discrimination test, 13 patients had sensory recovery from 11 mm to 20 mm after 6 months postoperatively. Conclusion: Reconstruction of the lower extremity with anterolateral thigh perforator free flaps after appropriate debridement is a good alternative way to use local or free muscle flaps.

• International Journal of Contents
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• v.11 no.2
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• pp.15-19
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• 2015

In this paper, we propose an efficient document layout analysis algorithm that includes table detection. Typical methods of document layout analysis use the height and gap between words or columns. To correspond to the various styles and sizes of documents, we propose an algorithm that uses the mean value of the distance transform representing thickness and compare with components in the local area. With this algorithm, we combine a table detection algorithm using the same feature as that of the text classifier. Table candidates, separators, and big components are isolated from the image using Connected Component Analysis (CCA) and distance transform. The key idea of text classification is that the characteristics of the text parallel components that have a similar thickness and height. In order to estimate local similarity, we detect a text region using an adaptive searching window size. An improved adaptive run-length smoothing algorithm (ARLSA) was proposed to create the proper boundary of a text zone and non-text zone. Results from experiments on the ICDAR2009 page segmentation competition test set and our dataset demonstrate the superiority of our dataset through f-measure comparison with other algorithms.

• Archives of Plastic Surgery
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• v.32 no.6
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• pp.727-732
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• 2005

The treatment of wounds of the lower extremity caused by diabetes or vascular dysfunction remains a difficult problem for the plastic surgeon. The use of negative pressure in wound healing is a relatively new method to facilitate chronic wound healing by secondary healing. The use of vacuum-assisted closure(VAC) system is purposed to reduce local edema, increase regional blood flow, enhance epithelial migration, preserve a moist wound environment, reduce bacterial colonization, promote granulation tissue formation, and mechanically enhance wound closure. The VAC also can be used as a dressing for anchoring an applied split thickness skin graft. We reviewed the data from 20 consecutive patients with non-healing wound in lower extremity at Dong-A University from March 2002 to December 2004. We used the VAC in 20 patients and compared the results with the control group. In the VAC using group, mean application duration was about 3 weeks and dressing change was done every other day. The follow-up period of patients ranged from 3 months to 30 months with a mean of 17 months. The points of comparison with control group are wound size, granulation tissue proliferation rate, operation method, preoperative time, postoperative healing time, complication, and cost. With those points, we propose to approve the efficiency of the VAC in non-healing wound. As a result, the VAC used in non-healing wound decrease wound size, accelerate granulation tissue formation, do a wound closure with less invasive operation method, make less postoperative complication, can make operation time shorter. Therefore it is cost effect. Our results demonstrate the usefulness of VAC as an adjunct in management of chronic wounds with other extrinsic factors.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.608-617
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• 2017

Methods of contrast enhancement have problem such as side effect of over-enhancement with non-gaussian histogram distribution, tradeoff enhancement efficiency against brightness preserving. In order to enhance contrast at various histogram distribution, segmentation to region with gaussian distribution and then enhance contrast each region. First, we segment an image into several regions using GMM(Gaussian Mixture Model)fitting by that k-mean clustering and EM(Expectation-Maximization) in $L^*a^*b^*$ color space. As a result region segmentation, we get the region map and probability map. Then we apply local contrast enhancement algorithm that mean shift to minimum overlapping of each region and preserve brightness histogram equalization. Experiment result show that proposed region based contrast enhancement method compare to the conventional method as AMBE(AbsoluteMean Brightness Error) and AE(Average Entropy), brightness is maintained and represented detail information.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2197-2204
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• 2015

In recent years, medical image diagnosis has growing significant momentous in the medicinal field. Brain and lung image of patient are distorted with salt and pepper noise is caused by moving the head and chest during scanning process of patients. Reconstruction of these images is a most significant field of diagnostic evaluation and is produced clearly through techniques such as linear or non-linear filtering. However, restored images are produced with smaller amount of noise reduction in the presence of huge magnitude of salt and pepper noises. To eliminate the high density of salt and pepper noises from the reproduction of images, a new efficient fuzzy based median filtering algorithm with a moderate elapsed time is proposed in this paper. Reproduction image results show enhanced performance for the proposed algorithm over other available noise reduction filtering techniques in terms of peak signal -to -noise ratio (PSNR), mean square error (MSE), root mean square error (RMSE), mean absolute error (MAE), image enhancement factor (IMF) and structural similarity (SSIM) value when tested on different medical images like magnetic resonance imaging (MRI) and computer tomography (CT) scan brain image and CT scan lung image. The introduced algorithm is switching filter that recognize the noise pixels and then corrects them by using median filter with fuzzy two-sided π- membership function for extracting the local information.

• Journal of Korea Multimedia Society
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• v.6 no.3
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• pp.508-517
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• 2003

This paper presents perceptual model with a stochastic multiresolution characteristic that can be applied with watermark embedding in the biorthogonal wavelet domain. The perceptual model with adaptive watermarking algorithm embeds at the texture and edge region for more strongly embedded watermark by the SSQ. The watermark embedding is based on the computation of a NVF that has local image properties. This method uses non- stationary Gaussian and stationary Generalized Gaussian models because watermark has noise properties. The particularities of embedding in the stationary GG model use shape parameter and variance of each subband regions in multiresolution. To estimate the shape parameter, we use a moment matching method. Non-stationary Gaussian model uses the local mean and variance of each subband. The experiment results of simulation were found to be excellent invisibility and robustness. Experiments of such distortion are executed by Stirmark 3.1 benchmark test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10C
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• pp.975-981
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• 2007

In this paper, we propose a spatially adaptive image restoration algorithm using local and statistics and estimated noise. The ratio of local mean, variance, and maximum values with different window size is used to constrain the solution space, and these parameters are computed at each iteration step using partially restored image. In addition, the additive noise estimated from partially restored image and the local constraints are used to determine a parameter for controlling the degree of local smoothness on the solution. The resulting iterative algorithm exhibits increased convergence speed when compared to the non-adaptive algorithm. In addition, a smooth solution with a controlled degree of smoothness is obtained without a prior knowledge about the noise. Experimental results demonstrate that the proposed algorithm requires the similar iteration number to converge, but there is the improvement of SNR more than 0.2 dB comparing to the previous approach.

• Toxicological Research
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• v.19 no.1
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• pp.39-44
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• 2003

Two local irritation and skin sensitization studies of nonspecific immunostimulator, $BARODON^{\circledR}$ were carried out with New Zealand White rabbits and Hartley guinea pigs. In skin irritation test of male New Zealand White rabbits, body weights were not significantly changed and there were no responses after treatment for 24 or 72 hours and the Primary irritation index (P.1.1.) was '0'. And, in the eye irritation test, there were chemosis in some of rabbits. One of 3 rabbits in washing group was detected chemosis after 24 and 72 h following treatment and 2 of 6 rabbits in non-washing group were detected chemosis after 24h and 7 days following treatment. Therefore, total score is '4' after 24 h and '2' after 72 h following treatment by conforming article "some blood vessel are clearly hyperemic" . However evaluation value is non-irritant because M.O.I. (Mean ocular irritation index) score is below during the all experimental period and no significance through individuals and exposure time. In skin sensitization, the score of skin reaction was graded 1 with 0% sensitization rate. Taken together, these results indicate that $BARODON^{\circledR}$ may be non-irritant material. material.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.3
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• pp.375-385
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• 1996

Turbulent flow and heat transfer characteristics around staggered tube banks were studied using the 3-D Navier-Stokes equations and energy equation governing a steady incompressible flow, which were reformulated in a non-orthogonal coordinate system with cartesian velocity components and discretized by the finite volume method with a non-staggered variable arrangement. The predicted turbulent kinetic energy using RNG $k-{\varepsilon}$ model was lower than that of standard $k-{\varepsilon}$ model but showed same result for mean flow field quantities. The prediction of the skin friction coefficient using RNG $k-{\varepsilon}$ model showed better trend with experimental data than standard $k-{\varepsilon}$ model result. The inclined flow showed higher velocity and skin friction coefficient than transverse flow because of extra strain rate ($\frac{{\partial}w}{{\partial}y}$). Also, this was why the inclined flow showed higher local heat transfer coefficient than the transverse flow.