• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.49-53
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• 2021

The Fenton reaction is often used to evaluate the chemical durability of polymer membranes of Proton Exchange Membrane Fuel Cells (PEMFC). However, due to the violent reaction between hydrogen peroxide and iron ions, it is difficult to compare experimental data because of low reproducibility. In this study, we tried to find the reaction conditions to improve the reproducibility of the durability test of the membrane by the Fenton reaction. The hydrogen peroxide concentration was fixed at 30%, the iron ion concentration, temperature, stirring speed, and sample size were varied, and the fluorine ion concentration of the Nafion polymer membrane deteriorated by radicals was measured. When the iron ion concentration was increased or the membrane sample size was increased, and the reaction temperature was increased to 80 ℃, the experimental deviation increased, so an iron ion concentration of 10 ppm, a temperature of 70 ℃, and a sample size of 0.5 ㎠ were suitable.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.557-565
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• 2020

In order for thermal degradationIn, excore nuclear flux monitoring system, as a monitoring and signal processing methodology of reactor power, monitors neutron pulses generated during nuclear fission as frequency status, and converts them into DC voltage, and then log values resultantly. The methods realy applied in the nuclear power plant are to construct combination of counters and flip-flops, or diodes and capacitors up to now. These methodes are reliable for relative high frequencies, while not credible for reasonable low frequencies or extreme low values. Therefore, we developed the circuit that converts frequencies into DC voltages, into and into log DC values in the wide range from low Hz to several hundred high kHz. We proved their validities through testing them using real data used in nuclear power plant and analyzed their results. And, these methods will be used to measure the neutron level of excore nuclear flux monitoring system in nuclear power plant.

• Journal of radiological science and technology
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• v.44 no.4
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• pp.327-333
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• 2021

Magnetic resonance imaging(MRI) uses strong magnetic field to image the cross-section of human body and has excellent image quality with no risk of radiation exposure. Because of above-mentioned advantages, MRI has been widely used in clinical fields. However, the noise generated in MRI degrades the quality of medical images and has a negative effect on quick and accurate diagnosis. In particular, examining a object with a detailed structure such as brain, image quality degradation becomes a problem for diagnosis. Therefore, in this study, we acquired T2 weighted 3D data of multiple sclerosis disease using BrainWeb simulation program, and used quantitative evaluation factors to find appropriate slice thickness among 1, 3, 5, and 7 mm. Coefficient of variation and contrast to noise ratio were calculated to evaluate the noise level, and root mean square error and peak signal to noise ratio were used to evaluate the similarity with the reference image. As a result, the noise level decreased as the slice thickness increased, while the similarity decreased after 5 mm. In conclusion, as the slice thickness increases, the noise is reduced and the image quality is improved. However, since the edge signal is lost due to overlapped signal, it is considered that selecting appropriate slice thickness is necessary.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.76-84
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• 2022

Arrhythmia is a condition in which the heart beats abnormally or irregularly, early detection is very important because it can cause dangerous situations such as fainting or sudden cardiac death. However, performance degradation occurs due to personalized differences in ECG signals. In this paper, we propose arrhythmia classification using hybrid combination model of CNN-LSTM. For this purpose, the R wave is detected from noise removed signal and a single bit segment was extracted. It consisted of eight convolutional layers to extract the features of the arrhythmia in detail, used them as the input of the LSTM. The weights were learned through deep learning and the model was evaluated by the verification data. The performance was compared in terms of the accuracy, precision, recall, F1 score through MIT-BIH arrhythmia database. The achieved scores indicate 92.3%, 90.98%, 92.20%, 90.72% in terms of the accuracy, precision, recall, F1 score, respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.228-241
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• 2021

This study verified the performance change of a LiDAR when it detects road signs, which are potential cooperation targets for an autonomous vehicle. In particular, road signs of different colors and materials were produced and tested in controlled rainfall on the real road environment. The NPC and intensity were selected as the performance indicators, and a T-Test was used for comparison. The study results show that the performance of LiDAR for the detection of road signs was reduced with the increase of rainfall. The degradation of performance in retroreflective sheets was lesser than painted road signs, but at the amount of 40 mm/h or more, the detection performance of retroreflective sheets deteriorates to an extent that data cannot be collected. The performance level of black paint was lower than that of other colors on a clear day. In addition, the white sheet was most sensitively degraded with the increase in precipitation. These performance verification results are expected to be utilized in the manufacturing of road facilities that improve the visibility of sensors in the future.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.712-726
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• 2022

The purpose of this study is to find out what discourse the newspaper's articles produce and distribute about 'drug addiction' and to reveal the topography and meaning of the discourse. Data were collected by searching 'drug' 'drug addiction' as keywords for news articles in four daily newspapers in Korea. As a result of analyzing using Norman Fairclough's critical discourse analysis, first, the 'crime-punishment' discourse was dominant in textual analysis. Drug addiction is a social evil and a serious crime such as sex crimes, child crimes, and violence, so it should be strictly punished. Second, in the discourse practice analysis, drug addiction is a mental disease that needs treatment, so systematic management by the state is required. Third, in the socio-cultural practice analysis, drug addiction is a means of making money for economic benefit, is related to corruption of political power, and is an object that should be strongly controlled to prevent drug crimes from threatening the foundation of the state. Culturally, drug addiction stems from the motivation of pleasure seeking, and is the result of moral degradation. Through this analysis, the conversion to the 'disease-treatment' discourse and drug policies centered on treatment and rehabilitation were suggested as alternatives.

• Journal of Forest and Environmental Science
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• v.38 no.3
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• pp.141-151
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• 2022

Soil seed banks as natural storage of plant seeds play an important role in the maintenance and regeneration of watershed. Natural regeneration potential of the soil seed bank of Land use types (LUTs) in Ogun River watershed (ORW) was investigated. ORW was stratified using proportionate sampling technique into Guinea Savannah (GS), Rainforest (RF) and Swamp Forest (SF) Ecological Zones (EZs). Three LUTs: Natural Forest (NF), Disturbed Forest (DF) and Farmland (FL) were purposively selected in GS: GSNF, GSDF, GSFL; RF: RFNF, RFDF, RFFL and SF: SFNF, SFDF, SFFL, respectively. Systematic line transects was used in the laying of the sample plots. Sample plots of 25 m×25 m were established in alternate positions. Ten 1 m×1 m quadrats were randomly laid for soil core sampling from previously randomly selected ten plots. The core samples (10) were pooled per plot in each LUT and placed in individual trays. Ten trays with sterilized soil were used as control. The trays were watered regularly and checked for seedlings emergence fortnightly for 18 months. The experimental design used was 3×3 factorial experiments. ANOVA, Diversity index (H') and Similarity index (SI) were used to analyze the data. There was significant difference in seedling emergence among ecological zones and land use types (p<0.05). A total of 4,400 seedlings emerged from the soil samples. All species were distributed among 32 families. FL in the RF had the highest number of germinated seeds (705±37.33 seedlings) followed by DF in the RF (701±49.6 seedlings). The lowest emergence was in NF of the SF (199±28.41 seedlings). DF in the RF had highest number of species (34) distributed among 22 families. Emergence from soil seed bank of NF in ORW was generally with more of tree species than herbs that were predominant in FL and DF.

• Journal of Ocean Engineering and Technology
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• v.36 no.1
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• pp.32-40
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• 2022

Underwater optical images face various limitations that degrade the image quality compared with optical images taken in our atmosphere. Attenuation according to the wavelength of light and reflection by very small floating objects cause low contrast, blurry clarity, and color degradation in underwater images. We constructed an image data of the Korean sea and enhanced it by learning the characteristics of underwater images using the deep learning techniques of CycleGAN (cycle-consistent adversarial network), UGAN (underwater GAN), FUnIE-GAN (fast underwater image enhancement GAN). In addition, the underwater optical image was enhanced using the image processing technique of Image Fusion. For a quantitative performance comparison, UIQM (underwater image quality measure), which evaluates the performance of the enhancement in terms of colorfulness, sharpness, and contrast, and UCIQE (underwater color image quality evaluation), which evaluates the performance in terms of chroma, luminance, and saturation were calculated. For 100 underwater images taken in Korean seas, the average UIQMs of CycleGAN, UGAN, and FUnIE-GAN were 3.91, 3.42, and 2.66, respectively, and the average UCIQEs were measured to be 29.9, 26.77, and 22.88, respectively. The average UIQM and UCIQE of Image Fusion were 3.63 and 23.59, respectively. CycleGAN and UGAN qualitatively and quantitatively improved the image quality in various underwater environments, and FUnIE-GAN had performance differences depending on the underwater environment. Image Fusion showed good performance in terms of color correction and sharpness enhancement. It is expected that this method can be used for monitoring underwater works and the autonomous operation of unmanned vehicles by improving the visibility of underwater situations more accurately.

• Journal of the Korea Society of Computer and Information
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• v.28 no.1
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• pp.79-86
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• 2023

Construction is one of the oldest fields of providing human living comfort. However, despite the continuous development not only in IT but also in other fields, productivity degradation due to low automation is still serious. In particular, the use of the 4th industrial revolution technologies in construction is just beginning. Blockchain, which is one of the 4th industrial revolution technologies, is a type of a distributed database that is used to replicate, share, and synchronize data spread across different geographical locations, such as multiple sites, countries, or organizations. In this paper, we introduce the block chain and analyze use cases according to seven themes in construction. As a result of the analysis, it is expected to increase the understanding of blockchain in construction and provide usefulness for the development of various services in the future.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.55-61
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• 2012

Objectives : Allium Hookeri (AH) is a traditional herb to treat inflammatory diseases in India and Myanmar. Recently, AH cultivation was succeeded in South Korea. This study was performed to evaluate the anti-inflammatory effects of Korean AH in RAW264.7 cells, mouse macrophage cell line. Methods : To evaluate the anti-inflammatory effects of root of AH, we prepared the 70% ethanol extract, then we examined the productions of nitrite, and pro-inflammatory cytokines. To examine the nitrite, and cytokines, the RAW264.7 cells were treated with AH, then stimulated with lipopolysaccharide (LPS, 500 ng/ml) for 24 h. Then the cells were harvested for griess assay, ELISA and real-time reverse transcription polymerase chain reaction (RT-PCR). Also to detect the ability of AH to induce heme oxygenase-1 (HO-1), we examined the HO-1 expression using real time RT-PCR and western blot. Furthermore, we examined the mitogen activated-protein kinases (MAPKs) and nuclear factor kappa B (NF-${\kappa}B$) activation to find out the underlying mechanisms. Results : AH ethanol extract significantly inhibited the productions of nitrite and interleukin (IL)-$1{\beta}$. AH treatment increased the HO-1 expression dramatically at 1 h, then peaked at 3 h. When the HO-1 was inhibited by tin (Sn) protoporphryin-IX (SnPP), the anti-inflammatory action of AH was reversed. AH treatment inhibited the activation of p38, but not extracelluar signal-regulated kinase (ERK 1/2) and c-Jun $NH_2$-terminal kinase (JNK) and also the degradation of inhibitory kappa B a (Ik-$B{\alpha}$) in the LPS-stimulated RAW 264.7 cells. Conclusions : These data could suggest that AH exerts anti-inflammatory influences through up-regulation of HO-1 and deactivation of p38.