• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.523-541
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• 2023

As accessibility to 3D printers increases, there is a growing frequency of exposure to chemicals associated with 3D printing. However, research on the toxicity and harmfulness of chemicals generated by 3D printing is insufficient, and the performance of toxicity prediction using in silico techniques is limited due to missing molecular structure data. In this study, quantitative structure-activity relationship (QSAR) model based on data-centric AI approach was developed to predict the toxicity of new 3D printing materials by imputing missing values in molecular descriptors. First, MissForest algorithm was utilized to impute missing values in molecular descriptors of hazardous 3D printing materials. Then, based on four different machine learning models (decision tree, random forest, XGBoost, SVM), a machine learning (ML)-based QSAR model was developed to predict the bioconcentration factor (Log BCF), octanol-air partition coefficient (Log Koa), and partition coefficient (Log P). Furthermore, the reliability of the data-centric QSAR model was validated through the Tree-SHAP (SHapley Additive exPlanations) method, which is one of explainable artificial intelligence (XAI) techniques. The proposed imputation method based on the MissForest enlarged approximately 2.5 times more molecular structure data compared to the existing data. Based on the imputed dataset of molecular descriptor, the developed data-centric QSAR model achieved approximately 73%, 76% and 92% of prediction performance for Log BCF, Log Koa, and Log P, respectively. Lastly, Tree-SHAP analysis demonstrated that the data-centric-based QSAR model achieved high prediction performance for toxicity information by identifying key molecular descriptors highly correlated with toxicity indices. Therefore, the proposed QSAR model based on the data-centric XAI approach can be extended to predict the toxicity of potential pollutants in emerging printing chemicals, chemical process, semiconductor or display process.

• Korean Journal of Cognitive Science
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• v.23 no.2
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• pp.205-224
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• 2012

How would people who buy an insurance policy respond to a low probability risk with a high future cost? Presented with a scenario describing a low probability accident of a chemical plant, participants in four experiments were asked to rate their perception of the risk and also their intention to buy an insurance of a given premium, an insurance, or a ratio insurance. Participants differently responded only to ratio insurance when rating their perception of risk, not to either premium or insurance. The pattern of results in four experiments converged to the conclusion that ratio insurance, an ecologically valid cue, makes people sensitive to the level of risk expressed in low probabilities of an accident. Our results were consistent with the prediction generated by the ecological cue hypothesis which empathizes the importance of frequency over probability in risk perception (Gigerenzer, 2000).

• Journal of Korean Medicine Rehabilitation
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• v.24 no.1
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• pp.83-92
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• 2014

Objectives To evaluate the clinical usefulness between muscle energy techniques (MET) and transcutaneous electrical nerve stimulator (TENS), we performed both on elector spinae muscle of acute low back pain patients. Methods After performing MET and TENS, we compared both in terms of electrical activity. We performed MET or TENS on elector spinae muscle of acute low back pain patients in each group (n=15,15). After performing MET or TENS, we analyzed root mean square (RMS), median edge frequency (MEF) and asymmetry index (AI). Results 1. After performing MET on elector spinae muscle of acute low back pain patients, RMS was significantly decreased compared with before (p<0.005). 2. After performing TENS on elector spinae muscle of acute low back pain patients, RMS was significantly decreased compared with before (p<0.005). 3. After performing MET on elector spinae muscle of acute low back pain patients, asymmetric index was significantly decreased compared with before (p<0.05). Conclusions According to above results, performing MET on elector spinae muscle of acute low back pain patients has effect in terms of RMS and asymmetric index. And performing TENS on elector spinae muscle of acute low back pain patients also has similar effect in terms of RMS but has not in terms of asymmetric index.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.4
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• pp.422-427
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• 1998

The gene and genotypic frequencies of ${\kappa}$-casein (${\kappa}$-CN), ${\beta}$-lactoglobulin (${\beta}$-LG), growth hormone (bGH) and prolactin (bPRL) loci in Korean cattle were investigated using PCR-RFLP analyses. Genomic DNA samples were obtained from 290 cows and 30 AI bulls. In both cows and bulls, the most predominant genotypes of ${\kappa}$-CN, ${\beta}$-LG, bGH and bPRL loci were AB, BB, AA and AA, respecitively. The frequencies of A and B alleles for ${\kappa}$-CN locus were .612 and .388 for cows and .567 and .433 for bulls. The respective frequencies of A and B alleles for ${\beta}$-LG locus were .153 and .847 in cows and .217 and .783 in bulls. The frequencies of A and B alleles for bGH locus were .769 and .231 in cows and .784 and .216 in bulls, respectively. The frequencies of A and B alleles for bPRL locus were .678 and .322 for cows and .767 and .233 for bulls. Differences in frequencies of these alleles were not significant between cows and bulls at all loci examined. If the DNA polymorphisms of these candidate genes are associated with economically important traits, they could serve as genetic markers for genetic improvement in future marker-assisted selection programs in Korean cattle.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.192-195
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• 2005

The silicon thin film solar cells were fabricated by 13.56 MHz PECVD (Plasma-Enhanced Chemical-Vapor Deposition) and 60 MHz VHF PECVD (Very High-Frequency Plasma-Enhanced Chemical-Vapor Deposition). We focus on textured ZnO:Al films prepared by RF sputtering and post deposition wet chemical etching and studied the surface morphology and optical properties. These films were optimized the light scattering properties of the textured ZnO:Al after wet chemical etching. Finally, the textured ZnO:Al films were successfully applied as substrates for silicon thin films solar cells. The efficiency of tandem solar cells with $0.25 cm^2$ area was $11.8\%$ under $100mW/cm^2$ light intensity. The electrical properties of tandem solar cells were measured with solar simulator (AM 1.5, $100 mW/cm^2)$ and spectral response measurements.

• Korean Journal of Community Nutrition
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• v.16 no.5
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• pp.548-558
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• 2011

The purpose of this study was to compare eating habits and food attitudes between depressed and normal adults. The subjects were selected (n = 6217) from those who participated in the 2008 Korean National Health and Nutrition Examination Survey (KNHANES IV). The subjects were divided into the depressed (DG, n = 841) and normal groups (NG, n = 3969). DG was those who have depression now or who have experienced depressing feelings more than two weeks or per year. The general characteristics, anthropometric measurement, eating habits, the dietary guideline recognition and practices were compared by using chi-square test and t-test. Also the partial correlations were analyzed by SAS (Statistical analysis system, version 9.1) program. There was a significantly higher rate of DG among the female (74.32%), with low education (44.6%) and low-income (32.0%) subjects (p < 0.001). DG showed significantly lower snacking and dining out. There was significantly higher rate of DG who responded "none" in frequency of snack (27.10%) and dining out (29.50%) (p < 0.001). Also DG showed significantly lower rate of the subjects who ate with the family than NG. Also, DG showed significantly lower dietary guideline recognition level and practice than NG. Correlation between depression symptom and various factors showed that positive correlation with low snack intake and dining out frequencies. However, correlation was relatively weak. In conclusion, eating habits and recognition levels and practice of dietary guidelines of DG were significantly different from NG. DG showed significantly lower frequencies of snack, dining out, and eating with family.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.771-784
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• 2014

The purpose of this study was to estimate the relationships between dietary factors and the stress perception levels of College students. A survey was conducted in June, 2010, targeting 332 college students in Gwangju. General environmental factors, stress perception levels, dietary behaviors, and dietary action guide performance of the subjects were evaluated by questionnaire, and food intakes was determined by the 24-hour recall method. The results are summarized as follows.: The score of frequency experiencing was $45.1{\pm}16.9$ for male students, and $47.0{\pm}16.7$ for female students. The importance scores were $50.8{\pm}18.5$ for males, and $53.3{\pm}18.7$ for females. The total score for dietary action guide performance was $39.6{\pm}7.2$ for males and $40.6{\pm}6.5$ for females. Nutrient intake levels were evaluated based on dietary reference intake (DRI), revealing energy intakes to be 68.5% EER in males and 73.9% in females. The mean intakes of nutrient were 54.2% RI for calcium, 73.6% RI for riboflavin, and 51.2% RI for vitamin C but 203.6% AI for sodium, which indicates an imbalance in nutrient intake. Analysis of the correlations between stress perception levels and dietary factors, scholarship achievements, financial problems, future problems, value senses, and family relationships revealed significant correlations with general environment factors, dietary behaviors, Dietary action guide performance, and nutrient intakes (p<0.05). The higher the stress perception levels of the students, the higher the energy, coffee and alcohol intake, which predicts that appropriate stress control in college students will lead to better dietary habits. It is expected that the results above will be used as basic data for the development of proper nutrition education programs and stress control strategies.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.793-798
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• 2006

The quality characteristics of semen are important indicators of the fertility of a boar. Development of genetic markers for the semen quality in boars will be beneficial to the improvement of porcine fertility. We investigated the relationship between the polymorphisms of epidermal growth factor (EGF), prostaglandin-endoperoxide synthase 2 (PTGS2) and prolactin receptor (PRLR) genes, and semen quality traits in boars. The genomic DNA of 233 boars (157 Duroc and 86 Landrace) from a central testing station was subjected to genotyping for surveying gene frequency. The EGF, PTGS2 and PRLR genotypes were determined using the restriction fragment length polymorphism method. Thirty-seven normal, mature Duroc boars from an AI center were also genotyped and their semen quality traits were collected. The effect of genotype on semen quality traits was analyzed by the least-squares means method using data corrected for season. The frequencies of the AA genotype of EGF, PTGS2 and PRLR in Duroc boars were 0.14, 0.01 and 0.66, respectively. In Landrace, the frequencies of the AA genotype were 0.03, 0.09 and 0.62, respectively. Boars with the BB genotype in EGF, with the AB genotype in PTGS2 and with the AA genotype in PRLR had significantly better semen quality with a higher percentage of normal sperm and a lower percentage of immature sperm than those with other genotypes. These findings imply that polymorphisms of EGF, PTGS2 and PRLR genes might be used as markers for improving the semen quality of boars.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.310-315
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• 2014

The domestic maritime environment shows higher frequency of maritime accidents amidst greater traffic volume arising from increasing international seaborne trade and maritime leisure activities. To reduce such maritime accidents, there exist various kinds of safety navigation devices in the ship bridge aimed to mitigate burdens of navigators and support their accurate decision making. Amongst is the AIS considered very important, which is an automatic tracking system to assist understanding of the circumstances in the vicinity by receiving information of other ships and also sending its own; where the information contains errors initially, however, such wrong information is periodically transmitted, accordingly giving rise to hindrance sometimes in decision making by shore operators or ship navigators at sea. This study is to propose the error data and field management algorithm using fuzzy theory toward improving reliability and accuracy in ship related information received from AIS.

• The Journal of the Acoustical Society of Korea
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• v.39 no.5
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• pp.454-460
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• 2020

Artificial intelligence assistants that provide speech recognition operate through cloud-based voice recognition with high accuracy. In cloud-based speech recognition, Wake-Up-Word (WUW) detection plays an important role in activating devices on standby. In this paper, we compare the performance of Convolutional Neural Network (CNN)-based WUW detection models for mobile devices by using Google's speech commands dataset, using the spectrogram and mel-frequency cepstral coefficient features as inputs. The CNN models used in this paper are multi-layer perceptron, general convolutional neural network, VGG16, VGG19, ResNet50, ResNet101, ResNet152, MobileNet. We also propose network that reduces the model size to 1/25 while maintaining the performance of MobileNet is also proposed.