• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.343-345
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• 2017

In digital era image processing has been utilized in a variety of media such as TV, camera and smart phone. However, in the process of analyzing, recognizing, and processing image data, deterioration occurs due to various causes and Salt & Pepper noise occurs. Typical methods for removing such noise include SMF, CWMF, and SWMF. However, existing methods have a somewhat poor noise canceling characteristic in Salt & Pepper noise environment. Therefore, in this paper, we propose an algorithm to remove Salt & Pepper noise effectively by using bilinear interpolation method and median filter according to noise density of local mask. And using the PSNR(Peak Signal to Noise Ratio) it compared to the existing methods and their performance in order to determine the performance of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1284-1289
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• 2016

Recently, digital image processing is applied a lot to the broadcasting, communication, computer graphic, and medical sectors. It generates noise when data is transmitted. There are many kinds of noises that add to the image such as salt and pepper noise, AWGN, and complex noise. Thus, this study divides the corrupted image into four4 areas and estimates the types of noises each pixel, and this study suggested a switching filter that separates the estimated into salt and pepper noise and AWGN. In the case that center pixel of local mask is corrupted by salt and pepper noise, it used a histogram probability weighting of subdivided area. Also, in case that it is corrupted by AWGN, algorithm that is applied to with different weights given for the distribution of each area with using subdivided area's distribution was suggested. For an objective comparison and conclusion, this study used PSNR and compared to existing methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2167-2172
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• 2015

Due to the recent progress in information technology, demand for video imaging devices such as displays has grown. In general, images experience deterioration during the process of transmission due to various reasons. Many studies have boon undertaken on ways o reduce such noise. This paper6 suggests an algorithm that makes a judgment on the noise in order to remove the salt & pepper noise and replaces original pixels if they are non-noise while processing noise according to its density. The suggested algorithm shows a high PSNR of 30.49[dB] for Goldhill images that had been damaged of a high density salt & pepper noise(P = 60%), Compared to the exising CWMF, SWMF, and A-TMF, there were improvements by 17.74[dB], 11.52[dB], and 13.76[dB], respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.10
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• pp.1320-1326
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• 2018

Digital video equipment is important in the 4th industrial revolution and is widely used in different fields for various purpose. Data of digital video equipment is exposed to noise due to different reasons including user environment and processing and such noise affect output and processing method. This can even cause error, resulting in decreased reliability of the equipment. In this research, it offers algorithm to effectively recover video by removing noise and impulse noise occurring during the process of channel delivery. This proposed algorithm recovers video by exploring valid pixel using directional local mask and noise determination. Then, valid pixel calculated goes through the final output calculation through comparative analysis on estimation. For comparing suggested method and algorithm, simulation is carried out. For checking the function of it, PSNR and profile are analyzed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1373-1379
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• 2007

A modified adaptive switching median filter for impulse noise removal, which has the noise detection step and the noise filtering step, is proposed in this paper. In the noise detection step, we use the detection threshold which is earned by calculating the intensity differences between pixels nearby with each other in localized window, to determine whether the pixels in the image are noise or not. Then in the noise filtering step, we will only remove the corrupted pixels and remain the good pixels. By the noise detection result, we can easily get the local noise density of the image, and use it to consider the filtering mask size and the times of filtering iteration according to different localized noise corruptions. For Setting the simulation result, we compared the proposed method to conventional median filters with several test images corrupted by various impulse noise densities. We also use the peak signal-to-noise ratio (PSNR) to evaluate restoration performance, the simulation results demonstrate that the proposed method shows better results than other median-based type filters.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.9
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• pp.1176-1182
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• 2021

Recently, with the development of artificial intelligence and IoT technology, automation, and unmanned work are progressing in various fields, and the importance of image processing, which is the basis of AI object recognition, is increasing. In particular, in systems that require detailed data processing, noise removal is used as a preprocessing step, but the existing algorithm does not consider the noise level of the image, so it has the disadvantage of blurring in the filtering process. Therefore, in this paper, we propose a modified Gaussian filter that determines the weight by determining the noise level of the image. The proposed algorithm obtains the noise estimate for the AWGN of the image using quadtree segmentation, determines the Gaussian weight and the pixel weight, and obtains the final output by convolution with the local mask. To evaluate the proposed algorithm, it was simulated compared to the existing method, and superior performance was confirmed compared to the existing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1076-1081
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• 2019

In response to the recent development of IT technologies, there are more demands for visual devices such as display. However, noise is generated in the process of sending video data due to various reasons. Noise is the representative noise which is commonly found. While A-TMF, CWMF, and AMF are the typical ways for removing Salt and Pepper noise, the noise is not removed well in high-density noise environment. To remove the noise in the high-density noise environment, this study suggested an algorithm which identifies whether it's noise or not. If it's not a noise, matches the original pixel. If it's a noise, divide the $3{\times}3$ local mask into the area of the element treated and the area of the element to be processed. Then, algorithm proposes to apply different weights for each element to treat it as an average filter. To analyze the performance of the algorithm, this study compared PSNR to compare the algorithm with other existing methods.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.2
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• pp.23-30
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• 2021

PURPOSE: Physical therapists are at risk of becoming infected because they are in contact with or within 2 meters of the patient while treating them. The purpose of this study is to investigate the anxiety and depression of physical therapists during the coronavirus disease 2019 (COVID-19) pandemic and to identify the factors that affect anxiety and depression. METHODS: A cross-sectional survey was conducted during the pandemic. The survey were completed by 84 physical therapists in 24 local hospitals in Gwangju, South Korea. The Generalized Anxiety Disorder-7 (GAD-7) scale and the Patient Health Questionnaire-9 (PHQ-9) were used to evaluate their anxiety and depression status. Logistic regression models were used to identify the general characteristics factors related to anxiety or depression. RESULTS: It was found that 40 (47.6%) respondents had anxiety, and 37 (44%) had depression. If there was a child under the age of seven in the physical therapist's family, a high probability of anxiety (p < .05) prevailed. Physical therapists in their 30s had a higher risk of depression than those in their 40s (p < .05). The risk of anxiety and depression in physical therapists who were with patients who did not wear masks was higher than for those who were with patients who wore masks (p < .05). CONCLUSION: The anxiety and depression status of physical therapists in Gwangju, South Korea, during the pandemic of COVID-19 was poor. It is necessary to wear a mask for all people during physical therapy.

• Korean Journal of Heritage: History & Science
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• v.37
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• pp.91-120
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• 2004

The Yan mountain area of the northern part of Hebei province and its local neighbor area is categorized main-distribution area of the northern bronze culture of the Eastern Zhou period(770bc~221bc). Recently, it was discovered the concrete character of the culture by a large scale excavation of the Yuhuangmiao cemetery at Jundu mountain. In the chinese scholarship, the cultural character of this area has established the independent cultural type that is distinguished from the Bronze culture of existing. In this paper, I have as a target of analysis remains relate to the Yuhuangmiao culture of the mountain area of northern Hebei in the Eastern Zhou period. And I would like to judge about diverse infuluential relationships of the character of the Yuhuangmiao curture and the Bronze culture, especially burials, burial customs and the characters of the excavated article. In particular, diverse infuluential relationships of the upper Xiajiadian culture Ordos bronze culture and The Central Plains cultural from The Yan state have a important meaning to understand about the character of the Yuhuangmiao culture and the beginning development process. Ultimately, it is peculiar characters of the Yuhuangmiao culture that a shaft gave with stone compartment protecting a coffin as a symbolic form, mask-burial customs such as mainly burials of the living with the dead dogs, a drum shaped jar, a tripod jar with two handles, a short bronze sword with circle hilt, Central Plains cultural bronze containers, bronze halberd and horse-shaped accessories of cartage horse trapping are distinguished from a local neighbor, the bronze culture from northern. The territory of time-space of The Yuhuangmiao culture can be dominately recognized bewteen the upper Xiajiadian culture and Ordos bronze culture. It is the Yan culture after the middle Warring States Period considering with the peculiar chacters which reflected by burials and bural customs and diverse infuluential relationships with peripheral cultures.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.446-452
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• 2014

Objective: This study aimed to evaluate the exposure status of formaldehyde(FA) among the nurses in ambulatory care departments of university hospital. Methods: Two university hospitals were surveyed. The FA concentration in air were measured to target 62 nurses in 8 ambulatory care departments(89 samples). Air sampling and analysis of FA were carried out according to the OSHA Method ID-205. The survey was conducted with questionnaire asking about how to control FA and whether the nurses use the formaldehyde protectors or not. Results: FA was detected in all samples. The maximum concentration of FA was 0.258 ppm and the geometric mean was 0.023 ppm. There was no sample that exceeded any of exposure standards by OSHA-TWA whereas there were 54 samples(60.7%) that exceeded the standards by NOISH-TWA. Among 62 nurses handling FA, 13 nurses(21.0%) used the protective gloves while nobody used a gas mask. It was assessed that any of 8 common ambulatory care departments did not use a safety cabinet for FA in which local exhaust ventilation was fixed. Conclusions: Nurses in ambulatory care departments were exposed to FA. Therefore, the environment management of a workplace, the health management of a nurses, FA handling education and installing a FA cabinet with a local exhaust ventilation were needed because FA as a carcinogen was able to cause any cancer to a human body if it was emitted in air for long time.