• Geomechanics and Engineering
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• v.37 no.1
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• pp.49-64
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• 2024

Rocks undergoing repeated loading and unloading over an extended period, such as due to earthquakes, human excavation, and blasting, may result in the gradual accumulation of stress and deformation within the rock mass, eventually reaching an unstable state. In this study, a CNN-CCM is proposed to address the mechanical behavior. The structure and hyperparameters of CNN-CCM include Conv2D layers × 5; Max pooling2D layers × 4; Dense layers × 4; learning rate=0.001; Epoch=50; Batch size=64; Dropout=0.5. Training and validation data for deep learning include 71 rock samples and 122,152 data points. The AI Rock Constitutive Model learned by CNN-CCM can predict strain values(ε₁) using Mass (M), Axial stress (σ₁), Density (ρ), Cyclic number (N), Confining pressure (σ₃), and Young's modulus (E). Five evaluation indicators R², MAPE, RMSE, MSE, and MAE yield respective values of 0.929, 16.44%, 0.954, 0.913, and 0.542, illustrating good predictive performance and generalization ability of model. Finally, interpreting the AI Rock Constitutive Model using the SHAP explaining method reveals that feature importance follows the order N > M > σ₁ > E > ρ > σ₃.Positive SHAP values indicate positive effects on predicting strain ε₁ for N, M, σ₁, and σ₃, while negative SHAP values have negative effects. For E, a positive value has a negative effect on predicting strain ε₁, consistent with the influence patterns of conventional physical rock constitutive equations. The present study offers a novel approach to the investigation of the mechanical constitutive model of rocks under cyclic loading and unloading conditions.

• Korean Journal of Poultry Science
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• v.51 no.1
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• pp.21-26
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• 2024

This study was conducted to investigate the composition of the fatty acids in the breast meat of Red-brown Korean native chickens (KNC-R). This study used a total sample of three hundred eighty-two KNC-R (males: 190, females: 192). We used the fatty acid methyl ester (FAME) method to extract the fatty acids. A 2-way ANOVA of the R program was used to assess the effects of batch and sex on each fatty acid trait. Analysis of the fatty acid in the sampled population showed that the predominant fatty acid was oleic acid (C18:1; 28.252%) which is monounsaturated fatty acid (MUFA), followed by palmitic acid (C16:0; 20.895%), saturated fatty acid (SFA), and two omega-6 polyunsaturated fatty acid (PUFAs): linoleic (C18:2; 15.975%), and arachidonic (C20:4; 10.541%). Indices used to evaluate the nutritional quality of fat in the diet: ratio between PUFAs and SFAs (P/S), thrombogenicity index (TI), and atherogenicity index (AI) were calculated and were 0.959, 0.814, and 0.355, respectively. Currently, meat consumers need healthier fatty acids. Therefore, information on the content of fatty acid in chicken meat is very important for meat consumers in choosing the type of the meat to be consumed.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.216-224
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• 2005

Chromatography has now been used successfully to provide the requisite purity for human plasma-derived biop-harmaceuticals such as coagulation factors and immunoglobulins. Recently, increasing attention has been focused on establishing efficient cleaning procedures to prevent potential contamination by microorganisms as well as carry-over contamination from batch to batch. The purpose of present study was to develop a cleaning validation system for the assurance of virus removal and/or inactivation during chromatography process. In order to establish an assay system for the validation of virus clearance during chromatography cleaning process, a quantitative real-time PCR method for porcine parvovirus(PPV) was developed, since PPV, a model virus for human parvovirus B19, has a high resistance to a range of physico-chemical treatment. Specific primers for amplification of PPV DNA was selected, and PPV DNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be 1.5 $TCID_{50}/ml$. The established real-time PCR assay was successfully applied to the validation of PPV removal and cleaning during SP-Sepharose cation chromatography for thrombin purification and Q-Sepharose anion chromatography for factor VIII purification. The comparative results obtained by real-time PCR assay and infectivity titrations suggested that the real-time PCR assay could be a useful method for chromatography cleaning validation and that it could have an additive effect on the interpretation and evaluation of virus clearance during the virus removal process.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.247-252
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• 2005

The typical treatment method for fluoride polluted water is the flocculation and precipitation method which usually is capable of reducing the fluoride concentration down to the level of about 10 ppm. However, this method is no longer effective for the treatment of contaminated water having less than 10 ppm of fluorides. To remove fluorides in polluted water from the fluoride concentration between 1 to 10 ppm, several adsorbents were prepared mainly based on an activated alumina and the fluoride removal efficiencies of the adsorbents were analyzed. The best fluoride removal efficiency was obtained when the activated alumina treated by sulfuric acid was used as the adsorbent. A proper calcination temperature for the sulfuric acid contained activated alumina was found to be about $500^{\circ}C$. An adsorption isotherm for the adsorbent was also obtained by using Freundlich model. The values of the constants in Freundlich isotherm model were calculated to be K=6.63 and 1/n=0.29 based on the results obtained from the series of batch type adsorption experiments.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.148-154
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• 2007

This study was performed to evaluate the application of $TiO_2$ on the photocatalytic treatment of swine wastewater. $TiO_2$ sol was prepared by hydrothermal method with the agent ratio($(C_2H_5)_2NH_2\;mol/Ti(OC_3H_7)_4\;mol)=1$ and R ratio ($H_2O\;mol/Ti(OC_3H_7)_4\;mol)=42$. The effect of parameter on the removal efficiency of swine wastewater in a batch type immobilized photocatalyst system such as initial pH, intensity of UV, dosage of $TiO_2$, air flow rate, and concentration of $H_2O_2$ was examined. Wastewater was effectively eliminated in the presence of both UV light illumination and $TiO_2$. Photocatalytic activity was higher in acidic condition compared to neutral and alkaline conditions. In addition, photocatalytic activity increased with increasing UV light intensity, dosage of $TiO_2$, the flow rate of air and the amount of $H_2O_2$ added as an oxidant, but the excess amount of $H_2O_2$ dosage decreased the removal efficiency.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.152-156
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• 2016

Experimental research on the preparation of photocatalyst for the decomposition of brilliant blue FCF ($C_{37}H_{31}O_9N_2S_3Na_2$) was performed. $TiO_2$ and ZnO powders were prepared from titanium (IV) sulfate and zinc acetate at low reaction temperature and atmospheric pressure by hydrothermal precipitation method without calcination. In addition, $TiO_2$ was prepared with cationic surfactant CTAB (Hexadecyltrimethyl ammonium bromide) at the same conditions. The physical properties of prepared $TiO_2$ and ZnO, such as crystallinity, average particle size and absorbance, were investigated by XRD, Zeta-potential meter and DRS. And, the photocatalytic degradation of brilliant blue FCF has been studied in the batch reactor under UV radiation. For the photocatalysts prepared without CTAB, $TiO_2$ has smaller particle size and larger absorbance and photocatalytic reaction rate than ZnO. And $TiO_2$, prepared with CTAB whose concentration is 1/10 of that of precursor, shows 15% higher than that prepared without CTAB in final photocatalytic degradation ratio of brilliant blue FCF.

• Journal of Soil and Groundwater Environment
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• v.17 no.4
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• pp.63-72
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• 2012

The main objective of this study is to assess the compatibility between Korean ministry of environment (KME) standard and ISO (KS I ISO) standard for the determination of BTEX and TPH content in soil. We carried out comparison analysis for both methods using CRM and matrix spiked samples. In case of GC-MS analysis for BTEX, we got statistically (significance level: 0.05) the same results from KME standard (ES 07600.1) and ISO standard (KS I ISO 15009). However, it showed statistically (significance level: 0.05) different results when TPH was analyzed by KME standard (ES 07552.1) and ISO standard (KS I ISO 16703). To clarify the reason why both methods produced different results for TPH content, we also did some additional experiments in terms of differences in extraction, clean-up and target hydrocarbon range. Extraction with polar and non-polar compounds mixed solvent (acetone+n-heptane) of KS I ISO 16703 showed higher extraction efficiency than with only non polar solvent (dichloromethane) extraction of ES 07552.1 by about 9%. While column type clean-up of KS I ISO 16703 showed the reduction in TPH content between before and after clean-up, batch type of clean-up of ES 07552.1 did not show any changes in TPH content through clean-up process. The target hydrocarbon range of ES 07552.1 and KS I ISO 16703 is $C_8{\sim}C_{40}$ and $C_{10}{\sim}C_{40}$, respectively. From this point of view, kerosene and JP-8 contaminated soil showed higher RPD (relative producibility deviation) values between results by both method than that of lubricant or diesel contaminated soil. The higher content of hydrocarbon ($C_8{\sim}C_{10}$) in kerosene and JP-8 played an important role in increasing RPD values in addition to the effects caused by different solvents and clean-up method. Consequently, it was concluded that both methods (ES 07552.1 and KS I ISO 16703) were not compatible.

• Management & Information Systems Review
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• v.37 no.4
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• pp.41-62
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• 2018

As the volume of unstructured data increases through various social media, Internet news articles, and blogs, the importance of text analysis and the studies are increasing. Since text analysis is mostly performed on a specific domain or topic, the importance of constructing and applying a domain-specific dictionary has been increased. The quality of dictionary has a direct impact on the results of the unstructured data analysis and it is much more important since it present a perspective of analysis. In the literature, most studies on text analysis has emphasized the importance of dictionaries to acquire clean and high quality results. However, unfortunately, a rigorous verification of the effects of dictionaries has not been studied, even if it is already known as the most essential factor of text analysis. In this paper, we generate three dictionaries in various ways from 39,800 news articles and analyze and verify the effect each dictionary on the accuracy of document classification by defining the concept of Intrinsic Rate. 1) A batch construction method which is building a dictionary based on the frequency of terms in the entire documents 2) A method of extracting the terms by category and integrating the terms 3) A method of extracting the features according to each category and integrating them. We compared accuracy of three artificial neural network-based document classifiers to evaluate the quality of dictionaries. As a result of the experiment, the accuracy tend to increase when the "Intrinsic Rate" is high and we found the possibility to improve accuracy of document classification by increasing the intrinsic rate of the dictionary.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.226-232
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• 2013

To produce biobutanol, fermentation processes using clostridia that mainly produce acetone, butanol and ethanol are used. In this work, a dynamic model describing the metabolic reactions in an acetone-butanol-ethanol (ABE)-producing clostridium, Clostridium acetobutylicum ATCC824, was proposed. To estimate the 58 kinetic parameters of the metabolic network model with experimental data obtained from a batch fermentor, we used an efficient optimization method combining a genetic algorithm and the Levenberg-Marquardt method because of the complexity of the metabolism of the clostridium. For the verification of the determined parameters, the developed metabolic model was evaluated by experiments where genetically modified clostridium was used and the initial concentration of glucose was changed. Consequently, we found that the developed kinetic model for the metabolic network was considered to describe the dynamic metabolic state of the clostridium sufficiently. Thus, this dynamic model for the metabolic reactions will contribute to designing the clostridium as well as the fermentor for higher productivity.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.228-233
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• 2000

This study was carried out to estimate the possibility on the removal of phenols and anilines, which were contained in pulp or dye waste water, and the reusability of plant materials, shepherd's purse and turnip. Most of phenols catalyzed with shepherd's purse were removed more than 90% in the presence of $H_2O_2$, and the removal was ranged from 53.1% for 2,6-DMP to more than 99% for 2,4,6-TCP when turnip was used as catalysts. The removal of anilines catalyzed with shepherd's purse was ranged from 42.2% for 2-CA to 78.7% for 3,4-DCA in the presence of $H_2O_2$, and in case of turnip, from 31.5% for 2-CA to 90.0 % for 2,4-DCA. The reuse of plant materials was proved to be possible for not only the batch method but also the continuous method. No decreasing removal was observed during 30 cycles in waster water contaminated with 100ppm of 2,4-DCP. However, it was observed that the removal was decreased with increasing the number of cycles in higher concentration of 2,4-DCP(800ppm). Therefore, it could be suggested that the number of reusable cycles depends on the initial concentration of substrates.