• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.277-279
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• 2022

Rapid Development and adoption of AIS as a survailance tool has resulted in widespread application of data analysis technology, in addition to AIS ship trajectory clustering. AIS data-based clustering has become an increasingly popular method for marine traffic pattern recognition, ship route prediction and anomaly detection in recent year. In this paper we propose a route waypoint extraction by clustering ships CoG variance trajectory using Density-Based Spatial Clustering of Application with Noise (DBSCAN) algorithm in both port approach channel and coastal waters. The algorithm discovers route waypoint effectively. The result of the study could be used in traffic route extraction, and more-so develop a maritime anomaly detection tool.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.1028-1041
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• 2023

BACKGROUND/OBJECTIVES: This study aimed to analyze the potential of school meals in South Korea as a sustainable tool to reduce carbon emissions by focusing on animal- vs. plant-based protein foods. MATERIALS/METHODS: By using a stratified proportional allocation method, 536 out of the 11,082 schools nationwide were selected including 21 kindergartens, 287 elementary-, 120 middle- and 108 high schools. A total of 2,680 meals served for 5 consecutive days (June 21-25, 2021) were collected. We analyzed the average serving amounts of protein foods (animal- vs. plant-based) per meal and then, calculated the estimated average amounts of carbon emission equivalents per meal by applying the conversion coefficients. The t-test and analysis of variance were used for statistical analyses (α = 0.05). RESULTS: The average serving amount of animal-based protein foods per meal was 12.5 g, which was approximately 3 times higher than that of plant-based ones (3.8 g) (P < 0.001); the Meat-group had the highest average amount of 17.0 g, followed by Egg-group (9.6 g), Fish-group (7.6 g), and Beans-and-Nuts-group (3.8 g) (P < 0.05). Specifically, pork (25.1 g) was ranked first, followed by poultry (19.6 g), processed meat products (18.0 g). The estimated average amount of carbon emission equivalents of animal-based protein foods per meal was 80.1 g CO₂e, which was approximately 31 times higher than that of plant-based ones (2.6 g CO₂e) (P < 0.001); the Meat-group had the highest average amount of 120.3 g CO₂e, followed by Fish-group (44.5 g CO₂e), Egg-group (25.9 g CO₂e), and Beans-and-Nuts-group (2.6 g CO₂e) (P < 0.05). Specifically, processed meat products (270.8 g CO₂e) were ranked first, followed by pork (91.7 g CO₂e), and processed fish products (86.6 g CO₂e). CONCLUSIONS: The results implied that school meals with plant-based alternatives could be a sustainable tool to improve carbon footprint.

• Biomolecules & Therapeutics
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• v.6 no.4
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• pp.423-428
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• 1998

Aceclofenac is an orally effective non-steroidal anti-inflammatory agent of the phenylacetic acid derivative. Bioequivalence study of two aceclofenac preparations, the test drug (Senafe $n_{R}$: Daewon Phar-maceutical Company) and the reference drug (Airta $l_{R}$: Daewoong Pharmaceutical Company), was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Sixteen healthy male volunteers, 24$\pm$4 years old and 63.9$\pm$6.9 kg of body weight in average, were divided randomly into two groups and administered the drug orally at the dose of 100 mg as aceclofenac in a 2$\times$2 crossover study. Plasma concentrations of aceclofenac were monitored by HPLC method for 12 hr after administration. AU $Co_{-12h}$ (area under the plasma concentration-time curve from initial to 12 hr) was calculated by the linear trapezoidal method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{msx}$) were compiled directly from the plasma drug concentration-time data. Student's t-test indicated no significant differences between the formulations in these parameters. Analysis of variance (ANOVA) revealed that there are no differences in AU $Co_{12h}$, $C_{max}$ and $T_{max}$ between the formulations. The apparent differences between the formulations were far less than 20% (e.g., 0.25, 0.01 and 7.32 for AU $Co_{-12h}$, $C_{max}$. and $T_{max}$, respectively). Minimum detectable differences (%) between the formulations at $\alpha$=0.05 and 1-$\beta$=0.8 were less than 20% (e.g., 14.65, 12.47 and 15.46 for AU $Co_{-l2h}$, $C_{max}$ and $T_{max}$, respectively). The 90% confidence intervals for these parameters were also within $\pm$ 20% (e.g.,-10.19~10.68, -8.87~8.89 and -3.69~ 18.33 for AU $Co_{-12h}$, $C_{msx}$ and $T_{max}$, respectively). These results satisfy the bioequivalence criteria of KFDA guidelines, indicating that two formulations of aceclofenac are bioequivalent.quivalent.ivalent.ent.t.ent.

• Journal of Korean Neurosurgical Society
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• v.38 no.1
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• pp.47-53
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• 2005

Objective : Anti-malaria drugs may modulate tumor resistance to chemotherapeutic agents, but it has not been proven effective in the treatment of malignant gliomas. The aim of this study was to determine whether adequate pre-clinical data on co-administration of chemotherapeutic agents with anti-malaria drugs on malignant cell lines could be obtained that would warrant its further potential consideration for use in a clinical trial for malignant gliomas. Methods : Two malignant glioma cell lines [U87MG, T98G] were treated with chemotherapeutic agents alone or with anti-malaria drugs. Cells were incubated with drugs for 4 days. Following the 4-day incubation, drug sensitivity assays were performed using 3-[4,5-dimethyl-2-thiazol-2-yl] 2,5-diphenyltetrazolium bromide [MTT] assay following optimization of experimental conditions for each cell lines and cell viability was calculated. Results : In all of four chemotherapeutic agents[doxorubicin. vincrisitne, nimustine, and cisplatin], the cell viability was found to be markedly decreased when hydroxychloroquine was co-administered on both U87MG and T98G cell lines. The two way analysis of variance[ANOVA] yielded a statistically significant two-sided p-value of 0.0033[doxorubicin], 0.0005[vincrisitne], 0.0007[nimustine], and 0.0003[cisplatin] on U87MG cell lines and 0.0006[doxorubicin], 0.0421[vincrisitne], 0.0317[nimustine], and 0.0001[cisplatin] on T98G cell lines, respectively. However, treatment with chloroquine and primaquine did not induce a decrease in cell viability on both U87MG and T98G cell lines. Conclusion : Our data support further consideration of the use of hydroxychloroquine prior to systemic chemotherapy to maximize its tumoricidal effect for patients with malignant gliomas.

• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.72-76
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• 2010

We have developed the bio-electrode measuring the variance of the amount of acetylcholine affected by residual pesticide. The working electrode of the biosensor was made by combination of cobalt phthalocyanine and carbon organic compounds. The biosensors were constructed by screen-printing method. The principle of working electrode is similar to thiocholine sensor. We have fabricated the biosensor using standard screen printing method. Generally, the biosensor made by printing method formed thick film biosensor. When the electrodes were made by electrochemical cells, the generation of current by the addition of enzyme substrate was inhibited by standard solutions of organo-phosphate pesticides. The detection limit of sensor is about 0.5 $\mu{g}/L$ for carbofuran. We could improve the responsibility of the sensor by controlling the cobalt phthalocyanine and thiocholine concentration ratio. Also we have tested the EPN and Chlorpyrifos pesticides and found that the biosensor is applicable to fast determination of residual pesticides.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.102-112
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• 2022

This study investigated dietary habits and intra- and inter-specific food resource partitioning of co-occurring walleye pollock (Gadus chalcogrammus) and Pacific cod (G. macrocephalus) from the waters off the north-eastern coast of South Korea using stomach contents and stable isotopes (δ¹³C and δ¹⁵N) analyses. Both species are mesopelagic carnivores that consumed mainly benthopelagic crustaceans, but teleosts were also abundant in the diet of Pacific cod. Non-metric multidimensional scaling (nMDS) ordination and permutational multivariate analysis of variance (PERMANOVA) of dietary data revealed significant intra- and inter-specific dietary differences, i.e., food resource partitioning. Nitrogen stable isotope values (δ¹⁵N) were similar between walleye pollock and Pacific cod, but carbon stable isotope values (δ¹³C) were significant different, suggesting different trophic positioning. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. Ontogenetic changes in diet compositions were evident. As walleye pollock, they preyed more upon carid shrimps and cephalopods, but no such trend was observed in the diets of Pacific cod. While stable isotope values indicated that large-sized specimens of both species were significantly enriched in ¹⁵N relative to smaller conspecifics thus supporting these data. Consequently, in this study, both methodologies, i.e., stomach contents and stable isotope analyses, provided evidence of inter- and/or intra-specific dietary segregations and trophic niche partitioning between co-occurring walleye pollock and Pacific cod off eastern Korean waters.

• Transactions of Materials Processing
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• v.31 no.6
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• pp.376-383
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• 2022

The potential damage region of a WC-Co cemented carbide die is investigated for cold forging process of a wheel-nut by numerical simulation with its chemical composition considered. Numerical simulation is utilized to calculate internal stress, especially for the WC-Co die, during the forging process. Finite element model is established, in which the elasto-plastic properties are applied to the work-piece of bulk steel, and elastic properties are considered for the lower die insert of the WC-Co alloy. This stress analysis enables to distinguish the potential damage regions of the WC-Co die. The regions from calculation are comparatively analyzed along with the crack area observed in the die after repetitive manufacturing. Effect of chemical composition of the WC-Co is also evaluated on characteristics of potential damage region of the die with variance of mechanical properties considered. Derived from Mohr-Coulomb fracture model, furthermore, a new stress index is presented and used for die stress analysis. This index inherently considers hydrostatic pressure and is then capable of deducing wide range of its distribution for representing stress state by modification of its parameter implying pressure sensitivity.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.134-144
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• 1998

A comprehensive air quality monitoring was carried out to investigate the criteria concentration of air pollutant in indoor of subway stations of Seoul City. The samples were collected twice per year (the first and the second half of the year) at each sampling point from February to September in 1997. Sampling point of subway stations was ticket office and platform. The measurement of indoor air pollutants such as sulfur dioxide(SO$_2$), nitrogen dioxide(NO$_2$), carbon monoxide(CO), carbon dioxide(CO$_2$), total suspended particulate(TSP) was performed to determine the indoor air quality. Heavy metals(Pb, Cd, Cu, Cr, As, Hg) were also measured together with those air pollutants. The annual average concentration of CO$_2$ and TSP in subway stations were relatively high while those of heavy metals were within 10% of environmental recommended standard concentration in all stations. As results of regression analysis between line and line of air factors, the concentrations of CO, CO$_2$, TSP, Pb, Cd, Cr and Cu were highly correlated, but those of $SO_2, NO_2$ and Hg were not correlated. As results of regression analysis between ticket office and platform, the concentrations of heavy metals such as Cr and Cu were highly correlated. Results of oneway analysis of variance between the first and the second half of the year air factors also indicated that CO, CO$_2$, Cd, Cu, Hg were significant($\alpha$=0.01), respectively. The average contration of total suspended particulate(TSP) in subway line No. 1 was shown high concentration(200 $\mu g/m^3\cdot$ day) level.

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.1996-2004
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• 2007

In this study, the optimization of culture medium using a Sterigmatomyces elviae mutant was investigated using statistical analysis to increase the cell mass and lactosucrose ($^4G-{\beta}$-D-galactosylsucrose) production. In basal medium, the cell mass and lactosucrose production were 4.12 g/l and 140.91 g/l, respectively. However, because of the low cell mass and lactosucrose production, optimization of culture medium was carried out to increase the cell mass and lactosucrose production. Culture media were optimized by the S. elviae mutant using analysis of variance (ANOVA) and response surface methodology (RSM). Central composite designs using RSM were utilized in this investigation. Quadratic models were obtained for cell mass and lactosucrose production. In the case of cell mass, optimal components of the medium were as follows: sucrose 1.13%, yeast extract 0.99%, bactopeptone 2.96%, and ammonium sulfate 0.40%. The predicted maximum value of cell mass was about 5.20 g/l and its experimental value was 5.08 g/l. In the case of lactosucrose production, optimal components of the medium were as follows: sucrose 0.96%, yeast extract 1.2%, bactopeptone 3.0%, and ammonium sulfate 0.48%. Then, the predicted maximum value of lactosucrose production was about 194.12 g/l and the corresponding experimental value was about 183.78 g/l. Therefore, by culturing using predicted conditions, the real cell mass and lactosucrose production increased to 23.3% and 30.42%, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1788-1792
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• 2005

Eddy current sensor is representative instrument measuring gap to base metal and sensing trouble in base metal. The existing eddy current sensor works as measuring variance of sensor coil's inductance. But, sensor coil have phenomenon that not only inductance but also real resistance varies in real action. Conductivity and Permeability are main variable in sensor coil's varying impedance(inductance, real resistance). By searching relationship between conductivity-permeability and sensor coil's impedance, eddy current sensor gain advantage of elevation of accuracy, removal of alignment to each base metal, and continuous sensing to varying base metal.