• Journal of Conservation Science
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• v.31 no.3
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• pp.287-298
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• 2015

The formaldehyde is damage to the metal are known universally. However, the quantification of the damage level and degree of damage is not clear. This study was conducted to test the following steps using a gas corrosion tester, and then evaluated by the optical, chemical and physical measurement. First, it was confirmed the damage level of the metal specimen(silver, copper, iron, lead, brass) by the formaldehyde(0.5, 1, 10, 100, 500ppm). Second, weighted damage to the metal specimens were tested according to the temperature and humidity conditions under damage levels. Third, the damage of accelerated degradation metal specimens were examined under damage levles. As a result, at 500ppm / day, the optical, chemical and physical damage of lead have been identified, the optical damage of all metals are was observed. The optical damage of some specimens were weighted in $25^{\circ}C-50%$, $30^{\circ}C-50%$. Chemical damage to the lead specimen is 2.8 times, 1.3 times were weighted in $30^{\circ}C-80%$, $25^{\circ}C-80%$. Referring to formate ion concentration of the accelerated degradation metal, corrosion products of iron and brass were actived the reaction of the formaldehyde gas, oxide film of lead was blocked the reaction of formaldehyde gas.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.139-148
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• 2008

The direct inspection of the outward aspects by field engineers is the important and critical part for structural safety assessment according to the related reports. This study presents an improved method of the state assessment for concrete floor slab by separating and evaluating the individual damage types. First, the various types of damage symptoms are separated, which have been included and dealt in a group. Secondly, they are weighted and scored independently based on the present guide and references. Overall procedures other than the above are retained as same as possible to avoid the confusion. The proposed method is applied and tested to a performed assessment project for a bridge for validation. The result shows that it is reasonable and applicable in respect that it is able to make up for the controversial points of the present guide revealed in practices. Careful check of excessively deteriorated parts in addition to the reasonable assessment of system by this method grants the structural repair and reinforcement propriety and economy, and assures of more safety. Twofold appraisal of this approach expands the applicable areas of value engineering to the structural maintenance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.2
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• pp.149-156
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• 2017

Nuclear fuel requires high reliability and safety and therefore contains debris filtering devices to prevent failure-inducing debris from entering it. The debris filtering performance of nuclear fuel is one of the most important factors for fuel integrity. Therefore, the performance must be evaluated and the measurement must be reasonable. In this study, a calculation method of the comprehensive filtering efficiency using the weighted mean was proposed to establish a standard filtering efficiency index. To confirm the suitability of the proposed method, representative debris specimens were selected and the filtering efficiency with the weighted mean was compared with the efficiency of the arithmetic mean. The weighting factor of the weighted mean was introduced to produce a fair evaluation. In addition, the analysis of the debris filtering mechanism was performed according to the size of debris specimens, and the main dimensions of the filtering feature for commercial nuclear fuel.

• Biomedical Science Letters
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• v.3 no.2
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• pp.139-150
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• 1997

In order to investigate the effect of aging and the $H_2O$$_2$ localization in association with histological, ultrastructural, and cytochemical studies in lung tissue after interleukin-1$\alpha$(IL-1) induced lung injury, an acute lung injury was induced by instillation of IL-1 into the trachea. Both of 4- and 20-months-old male rats, protein contents in IL-1 treated branchoalveolar lavage increased significantly compared to each control rats. Acute lung injury occured by oxidative stress because neutrophils accumulated in vascular lumen and formed the adhesion with endothelial cells. As these cause, tissue proteins were exuded and leukocytes migrated into the alveolar lumen. Neverthless in these lung injury $H_2O$$_2$ localization of IL-1 treated 20 months rats was not different compared to IL-1 treated 4 months rats. After all aging was not a factor to accelate IL-1 induced lung injury. Based on these results, it is suggested that neutrophil infilteration might be an important cause in acute lung injury, and aging is not a factor to change the acute lung injury by oxidative stress.

• Journal of Conservation Science
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• v.30 no.4
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• pp.353-364
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• 2014

Formaldehyde(HCHO) may have a damage effect on Korean traditional textiles, because concentration is high and occurrence frequency is frequent at the exhibition room and storage area. Total 20 specimens were prepared using 4 different materials (silk, cotton, ramie, hemp) after dyeing with 5 colors (undyed, red, yellow, blue, black). The specimens were exposed to HCHO gas in the test chamber. The gas acceleration test was conducted to identify the deterioration of Korean traditional textiles according to HCHO concentration(0.5, 1, 10, 100, 500ppm), to temperature-humidity condition at HCHO 500ppm, and deterioration conditions at HCHO 500ppm. Optical, chemical, and physical evaluation was carried out after the exposure. The results, color difference, grey scale rating, formate($HCO_2{^-}$) of some textiles increased at 500ppm, while pH decreased at 500ppm. Also, color difference, grey scale rating, formate($HCO_2{^-}$) of some textiles increased double damage at high temperatures & humidity, high humidity condition. But, damages of accelerated degradation textiles were slight, because of degradation degree and degradation products. The results suggest that determined the damage to the korean traditional textile, damage level, damage-weighted condition, damage to accelerated degradation textiles. In addition, formaldehyde damaged to yellowing of red textiles, bleaching of accelerated degradation textiles, formic acid damaged to bleaching of total 20 specimens.

• KOREAN POULTRY JOURNAL
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• v.24 no.9 s.275
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• pp.166-169
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• 1992

닭의 바이러스성 간염은 닭에서 흔히 일어나는 질병 중의 하나는 아니다. 그러나 국내에서는 본질병의 전형적인 발생 예가 아직 검색되지 않았으나 외국의 대군사육계군에서 종종 발생하고 있어 국내에도 최근 대군사육화하면서 우려가 되는 질병으로 그중 스트레스에 의한 간염이 때때로 상당한 생산성 저하를 유발하기도 하며 산란율과 폐사율에서 경제적인 손상을 미치게하는 스트레스에 의해 발병이 가중되는 바이러스성 간염이 양계장 생산성에 미치는 영향에 대해 알아보고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.202-207
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• 2021

One of the most important tasks in image processing is noise filtering. Noise removal in image is a difficult task due to many reasons such as nonstationary sequences and corrupted by various types of noise. Human's visual perception is heavily based on the edge information. Thus, noise filtering must preserve edges. To remove the noise, we usually use the square-shaped median filter. They possess mathematical simplicity but have the disadvantages that blur the edges. In this paper we consider a new technique for image restoration using a weighted octagonal median filter. The technique consists of simple hypothesis test for edge detection, and we use the weighted octagonal-shaped moving window. The new technique is applied to noise corrupted image and experimental results are compared to the results of the square-shaped median filter and the cross-shaped median filter.

• The Journal of the Acoustical Society of Korea
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• v.22 no.4
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• pp.315-322
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• 2003

We propose a channel-attentive Mel frequency cepstral coefficient (CAMFCC) extraction method to improve the recognition performance of speech that is partially corrupted in the frequency domain. This method introduces weighting terms both at the filter bank analysis step and at the output probability calculation of decoding step. The weights are obtained for each frequency channel of filter bank such that the more reliable channel is emphasized by a higher weight value. Experimental results on TIDIGITS database corrupted by various frequency-selective noises indicated that the proposed CAMFCC method utilizes the uncorrupted speech information well, improving the recognition performance by 11.2% on average in comparison to a multi-band speech recognition system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.711-714
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• 2015

A new technique for image restoration using Weighted cross-shaped median filter with edge-detection algorithm is proposed in this paper. It consists of simple hypothesis test for edge-detection, and makes use of the weighted cross-shape window. This method is applied to noise corrupted image and its results are compared with those of median filters. As for the experimental result, method of weighted cross-shape median filter is superior to other median filters.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.109-115
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• 2012

In order to evaluate the effect of structural degradation of a GFRP composite bogie frame due to ballast-flying phenomena, the impact test and residual compression test after impact was conducted for glass fiber/epoxy 4-harness satin woven laminate composites applied to skin part of a bogie frame. The impact test was performed using a instrumented impact testing system with energy levels of 5J, 10J, and 20J, and the impactor was designed to have various ballast shapes such as sphere, cube, and cone to consider the ballasted track environments. The residual compression strength was tested to evaluate the degradation of mechanical properties of impact-damaged laminate composites. The results showed that the damage area and the degradation of residual compressive strength after impact for laminate composites was increased with increase of impact energy for all ballast shapes, and was particularly most influenced by ballast shape of cone.