• Journal of Aerospace System Engineering
• /
• v.17 no.1
• /
• pp.79-87
• /
• 2023

To design a control law of an aircraft, an accurate aircraft dynamic model is required. To obtain an aerodynamic database (DB) to build a dynamic model, a large number of wind tunnel tests are typically required. However, when flight test data of target aircraft exist such as in the process of unmanned conversion of a manned aircraft, an aircraft dynamic model can be obtained through a parameter estimation method and a DB tuning procedure. This paper describes a nonlinear model construction process and a verification method for KC-100 OPV aircraft. Flight data compatibility analysis was performed to determine suitability of the estimation method application. Linear model estimation was performed using the maximum likelihood estimation method. Results of aerodynamic DB tuning process and verification applying the FFS standard to the nonlinear model constructed are presented.

• Journal of Forest and Environmental Science
• /
• v.39 no.2
• /
• pp.105-117
• /
• 2023

Climate change and invasive alien plant species (IAPs) are having a significant impact on mountain ecosystems. The combination of climate change and socio-economic development is exacerbating the invasion of IAPs, which are a major threat to biodiversity loss and ecosystem functioning. Species distribution modelling has become an important tool in predicting the invasion or suitability probability under climate change based on occurrence data and environmental variables. MaxEnt modelling was applied to predict the current suitable distribution of most noxious weed A. adenophora (Spreng) R. King and H. Robinson and analysed the changes in distribution with the use of current (year 2000) environmental variables and future (year 2050) climatic scenarios consisting of 3 representative concentration pathways (RCP 2.6, RCP 4.5 and RCP 8.5) in Bhutan. Species occurrence data was collected from the region of interest along the road side using GPS handset. The model performance of both current and future climatic scenario was moderate in performance with mean temperature of wettest quarter being the most important variable that contributed in model fit. The study shows that current climatic condition favours the A. adenophora for its invasion and RCP 2.6 climatic scenario would promote aggression of invasion as compared to RCP 4.5 and RCP 8.5 climatic scenarios. This can lead to characterization of the species as preferring moderate change in climatic conditions to be invasive, while extreme conditions can inhibit its invasiveness. This study can serve as reference point for the conservation and management strategies in control of this species and further research.

• Food Science of Animal Resources
• /
• v.42 no.2
• /
• pp.280-294
• /
• 2022

This study aimed to evaluate the effectiveness of propolis extract as a natural preservative for livestock products in term of chemical and microbiological characteristics by meta-analysis. The stages carried out in this study were identification, selection, checking suitability, and the resulting selected articles were used in the meta-analysis. The selection results obtained a total of 22 selected journal articles consisting of 9 articles for analysis of the antimicrobial activity of propolis extract and 13 articles for analysis of the chemical and mirobiological characteristics of livestock products. The articles were obtained from electronic databases, namely Science Direct and Google Scholar. The model used in this study is the random-effect model involving two groups, control and experimental. Heterogeneity and effect size values were carried out in this study using Hedge's obtained through openMEE software. Forest plot tests and data validation on publication bias was obtained using Kendall's test throught JASP 0.14.1 software. The results showed that there is a significant relationship between propolis extract with the results of the antimicrobial activity (p<0.05). In addition, the results of the application of propolis extract on the livestock products for the test microbes and the value of thiobarbituric acid reactive substances (TBARs) showed significant results (p<0.05). Conclusion based on the random-effect model on the effectiveness of antimicrobial activity of propolis extract and their apllication as a natural preservative of the chemical and microbiological characteristics of livestock products is valid by Kendall's test (p>0.05). Propolis in this case effectively used as natural preservatives in livestock products.

• Journal of the Korean Society of Food Culture
• /
• v.25 no.6
• /
• pp.810-819
• /
• 2010

The objective of this study was to produce muffins with added dukeum ramie leaf powder and to compare them to a control. We used two different optimal composition ratios to produce muffins. The physical and sensory characters were varied by changing the ratio of dukeum ramie leaf powder, butter, and sugar to identify a critical value using response surface regression analysis. The ranges for the added dukeum ramie leaf powder, sugar, and butter were 15-35, 60-100, and 60-100 g, respectively. Muffins with added dukeum ramie leaves had comparable mineral and antioxidant vitamin compositions to those of dried ramie leaves. Muffins with added dukeum ramie leaf powder satisfied the suitability of the model, showing a p-value within 5% of significance level (p<0.05) for every aspect Volume and height differed without any association to ingredients. Lightness increased when less dukeum ramie leaf powder was added with more butter and sugar, redness increased when more dukeum ramie leaf powder and sugar were added with 70-80 g of butter, whereas yellowness increased when less dukeum ramie powder was added. Texture and toughness increased when less dukeum ramie leaf powder was added. The degree of gumminess and chewiness depended hugely on the amount of sugar. Cohesiveness, decreased with more dukeum ramie leaf powder and butter, whereas hardness increased with a medium range of ingredients. Sensory character increased with less dukeum ramie powder, and overall quality increased with more butter and sugar, but depended on the amount of added dukeum ramie power. The critical values from the sensory characteristics showed that 27 g of dukeum ramie powder, 72 g of sugar, and 86 g of butter was optimum.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.46 no.3
• /
• pp.186-197
• /
• 2023

In this study, we focus on the improvement of data quality transmitted from a weather buoy that guides a route of ships. The buoy has an Internet-of-Thing (IoT) including sensors to collect meteorological data and the buoy's status, and it also has a wireless communication device to send them to the central database in a ground control center and ships nearby. The time interval of data collected by the sensor is irregular, and fault data is often detected. Therefore, this study provides a framework to improve data quality using machine learning models. The normal data pattern is trained by machine learning models, and the trained models detect the fault data from the collected data set of the sensor and adjust them. For determining fault data, interquartile range (IQR) removes the value outside the outlier, and an NGBoost algorithm removes the data above the upper bound and below the lower bound. The removed data is interpolated using NGBoost or long-short term memory (LSTM) algorithm. The performance of the suggested process is evaluated by actual weather buoy data from Korea to improve the quality of 'AIR_TEMPERATURE' data by using other data from the same buoy. The performance of our proposed framework has been validated through computational experiments based on real-world data, confirming its suitability for practical applications in real-world scenarios.

• Journal of dental hygiene science
• /
• v.23 no.4
• /
• pp.369-377
• /
• 2023

Background: In this study, we investigated the potential use of keratin for oral tissue regeneration. Keratin is well-known for its effectiveness in skin regeneration by promoting keratinization and enhancing the elasticity and activity of fibroblasts. Because of its structural stability, high storability, biocompatibility, and safety in humans, existing research has predominantly focused on its role in skin wound healing. Herein, we propose using keratin proteins as biocompatible materials for dental applications. Methods: To assess the suitability of alpha-keratin protein as a substrate for cell culture, keratin was extracted from human hair via PEGylation. Viabilities of primary human gingival fibroblasts (HGFs) and human oral keratinocytes (HOKs) were assessed. Fluorescence immunostaining and migration assays were conducted using a fluorescence microscope and confocal laser scanning microscope. Wound healing and migration assays were performed using automated software to analyze the experimental readout and gap closure rate. Results: We confirmed the extraction of alpha-keratin and formation of the PEG-g-keratin complex. Treatment of HGFs with keratin protein at a concentration of 5 mg/ml promoted proliferation and maintained cell viability in the test group compared to the control group. HOKs treated with 5 mg/ml keratin exhibited a slight decrease in cell proliferation and activity after 48 hours compared to the untreated group, followed by an increase after 72 hours. Wound healing and migration assays revealed rapid closure of the area covered by HOKs over time following keratin treatment. Additionally, HOKs exhibited changes in cell morphology and increased the expression of the mesenchymal marker vimentin. Conclusion: Our study demonstrated the potential of hair keratin for soft tissue regeneration, with potential future applications in clinical settings for wound healing.

• Journal of Korean Society of Forest Science
• /
• v.102 no.1
• /
• pp.90-96
• /
• 2013

This study was conducted to investigate a stability trend within 6 above average and 4 blow average erosion control dams, which were selected by The Korean Association of Soil and Water Conservation and were built in 1990s in Gyeonggi and Gangwon Province. The study was aimed to measure rebound hardness of upstream face, flood way and downstream face from those dams selected by using 'Concrete Test Hammer'. The main purposes of the study are selection of compression strength prediction equation and scope of wavelength, which successfully demonstrate non-destructive test results for erosion control dams. There is an opportunity to increase disaster prevention ability when stability vulnerability of concrete erosion control dam is detected in a timely manner. Results of the compression strength investigation express that there is a consistency with visual inspection of stability that has been processed by The Korean Association of Soil and Water Conservation. We concluded that a prediction equation, which was developed by Architectural Institute of Japan (AIJ), shows highest suitability in Korean erosion control dams when stability investigation is performed. The detailed criteria for the test result are 'stable', 'detail inspection required' and 'poor' for over 300 $kgf/cm^2$, 250~300 $kgf/cm^2$ and below 250 $kgf/cm^2$ respectively. Standards for stability of Korean erosion control dam and a compression strength prediction equation (that corresponds to the standards of the stability) should be established on the basis of chronological data of erosion control dam compression strength. Systematical approach for stability inspection that carries out remodeling or repair when problem on erosion control structures are detected through visual inspection and simple stability test, is necessary for the future disaster prevention.

• Journal of Bio-Environment Control
• /
• v.23 no.3
• /
• pp.250-255
• /
• 2014

Sterilization is an important factor in reprocessing of drained nutrient solution (RDN). To evaluate the suitability of ozone microbubble for RDN in protected horticulture and plant factory, strong fungicidal activity of ozone and microbubble were applied. This experiment was taken advantage of ozonated water (OW) and ozone gas (OG). The Fusarium oxysporum (FO), Phytophthora capsici (PC) and Colletotrichum gloeosporioides (CG) were treated with OW 0.5, 1.0 and 2.0 ppm and OG $3.0g{\cdot}h^{-1}$ for 0, 30, 60, 120 and 180 sec. Results of this experiment can be summed up as follows : In the OW, FO was sterilized by 0.5 ppm in 60 sec and PC was sterilized by 2.0 ppm in 30 sec. In the OG, FO and PC both of them were sterilized in 180 sec. However, CG was not sterilized using OW and OG. Overall, ozone microbubble showed possibility of sterilization in RDN. However, CG is required to more ozone concentration and processing time.

• Journal of Pharmaceutical Investigation
• /
• v.35 no.3
• /
• pp.137-142
• /
• 2005

A rapid, selective and sensitive reversed-phase HPLC method for the determination of glipizide in human serum was validated and applied to the pharmacokinetic study of glipizide. Glipizide and internal standard, tolbutamide, were extracted from human serum by liquid-liquid extraction with benzene and analyzed on a Nova Pak $C_{18}\;60{\AA}$ column with the mobile phase of acetonitrile-potassium dihydrogen phosphate (10 mM, pH 3.5) (4:6, v/v). Detection wavelength of 275 nm and flow rate of 0.7 ml/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^3$ factorial design using a fixed glipizide concentration (500 ng/ ml) with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 10-1000 ng/ml with correlation coefficient greater than 0.999. The lower limit of quantitation using 0.5 ml of serum was 10.0 ng/ml, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 82.6 to 105.0% for glipizide with overall precision (% C.V.) being 1.13-13.20%. The percent recovery for human serum was in the range of 85.2 93.5%. Stability studies showed that glipizide was stable during storage, or during the assay procedure in human serum. The peak area and retention time of glipizide were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of glipizide in human serum samples for the pharmacokinetic studies at three different laboratories, demonstrating the suitability of the method.

• Journal of Pharmaceutical Investigation
• /
• v.35 no.6
• /
• pp.437-443
• /
• 2005

A rapid, selective and sensitive reversed-phase HPLC method for the determination of a major metabolite of terfenadine, fexofenadine, in human serum was developed, validated, and applied to the pharmacokinetic study of terfenadine. Fexofenadine and internal standard, haloperidol were extracted from human serum by liquid-liquid extraction with acetonitrile and analyzed on a $Symmetry^{TM}$ C8 column with the mobile phase of 1% triethylamine phosphate (pH 3.7)-acetonitrile (67:33, v/v, adjusted to pH 5.6 with triethylamine). Detection wavelength of 230 nm for excitation, 280 nm for emission and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed fexofenadine concentration (50 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 10-500 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 10 ng/mL, which was sensitive enough for the pharmacokinetic studies of terfenadine. The overall accuracy of the quality control samples ranged from 95.70 to 114.58% for fexofenadine with overall precision (% C.V.) being 3.53-14.39%. The relative mean recovery of fexofenadine for human serum was 90.17%. Stability studies (freeze-thaw, short-term, extracted serum sample and stock solution) showed that fexofenadine was stable during storage, or during the assay procedure in human serum. However, the storage at $-70^{\circ}C$ for 4 weeks showed that fexofenadine was not stable. The peak area and retention time of fexofenadine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of fexofenadine in human serum samples for the pharmacokinetic studies of orally administered Tafedine tablet (60 mg as terfenadine) at three different laboratories, demonstrating the suitability of the method.