• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.124-132
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• 2022

By-products from fisheries produced in Korea are of the same industrial material as imported raw materials and are valuable resources for marine bioindustries. Securing raw materials for the mass production of functional materials is one of the main objectives for marine bioindustrial development. The use of fishery by-products as raw materials is anticipated to increase rapidly as the biomarket is growing into a promising industry. In this study, data were acquired from an open-source environment to perform exploratory data analysis, and various visualization methods were used to compare fishery production to the production of marine processed products in the year 2020. This study suggested that the amount of seafood processing, types of processing items, and areas where fishery processing residue is generated, should be able to secure hygienic raw material supply in large quantities. Thus far, it has been found that the Gyeonggi-do and Busan province, where HACCP-certified processing facilities are concentrated, and the local government Seafood Cluster and the Smart Aquaculture Cluster are at the forefront of stable, mass production of raw materials.

• Smart Media Journal
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• v.6 no.1
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• pp.9-15
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• 2017

The trends in ICT are concentrated in IoT, Bigdata, and Cloud Computing. These mega-trends do not operate independently, and mass storage technology is essential as large computing technology is needed in the background to support them. In order to evaluate the performance of high-capacity storage based on open source Ceph, we carry out the demonstration test of Abyss Storage with domestic and overseas sites using educational network KOREN. In addition, storage media and network bonding are tested to evaluate the performance of the storage itself. Although there is a substantial difference in aspect of the physical speed among storage medias, there is no significant performance difference in the storage media test performed. As a solution to this problem, we could get performance improvement through network acceleration. In addition, we conducted actual performance test of Abyss Storage internal and external network by connecting domestic and overseas sites using KOREN network.

• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.12-17
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• 2019

Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in fresh-cut salads available from the market were determined by gas chromatography-mass spectrometry (GC-MS). The target compounds in 3 g of acidified homogenates were extracted with 20 mL of methyl t-butyl ether (MTBE). The extract was concentrated to 1 mL and heated for 1 h at $55^{\circ}C$. The analytes were separated using a DB-1701 column and detected with a mass spectrometer. The method detection limit was approximately $6{\mu}g/kg$, and both analytical accuracy and precision were found to be satisfactory. The linearity of the calibration curves expressed as the coefficients of determination was >0.996. The analysis of seven samples using the established method showed that the four samples contained considerable amounts of analytes ($25.4-31.2{\mu}g/kg$ of DCAA and $18.8-46.1{\mu}g/kg$ of TCAA). These results raised a concern about the impact of fresh-cut salad consumption on human health.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.873-884
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• 2024

Flunixin is a veterinary nonsteroidal anti-inflammatory agent whose residues have been investigated in their original form within tissues such as muscle and liver. However, flunixin remains in milk as a metabolite, and 5-hydroxy flunixin has been used as the primary marker for its surveillance. This study aimed to develop a quantitative method for detecting flunixin and 5-hydroxy flunixin in milk and to strengthen the monitoring system by applying to other livestock and fishery products. Two different methods were compared, and the target compounds were extracted from milk using an organic solvent, purified with C₁₈, concentrated, and reconstituted using a methanol-based solvent. Following filtering, the final sample was analyzed using liquid chromatography-tandem mass spectrometry. Method 1 is environmentally friendly due to the low use of reagents and is based on a multi-residue, multi-class analysis method approved by the Ministry of Food and Drug Safety. The accuracy and precision of both methods were 84.6%-115% and 0.7%-9.3%, respectively. Owing to the low matrix effect in milk and its convenience, Method 1 was evaluated for other matrices (beef, chicken, egg, flatfish, and shrimp) and its recovery and coefficient of variation are sufficient according to the Codex criteria (CAC/GL 71-2009). The limits of detection and quantification were 2-8 and 5-27 ㎍/kg for flunixin and 2-10 and 6-33 ㎍/kg for 5-hydroxy flunixin, respectively. This study can be used as a monitoring method for a positive list system that regulates veterinary drug residues for all livestock and fisheries products.

• Journal of Environmental Impact Assessment
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• v.4 no.2
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• pp.131-149
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• 1995

The object of this study is to suggest some alternatives for environmental management towards sustainable urban development of Chongju city in Korea. This study analyses urban environmental indicators (population density, land use, road, park, car, etc.), level of air and water pollution and solids waste generation by comparing Chongju city and other large cities. Some alternatives towards sustainable development in Chongju city would be summerized and suggested as higher concentrated land use(compact city), mixed land use, supply of mass transit, establishment of regional environmental standards, total emission regulation of air and water pollutants, the preparation of Local Agenda21 of Chongju, and the introduction of strategic environmental assessment(SEA) into environmental impact assessment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.9
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• pp.1385-1391
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• 1997

An analysis is presented on the stability of an elastic cantilever column subjected to a concentrated follower force as to the influence of the elastic restraint and a tip mass at the free end. The elastic restraint is formed by the rotatory springs. For this purpose, the governing equations and boundary conditions are derived by using Hamilton's principle, and the critical flutter loads and frequencies are obtained from the numerical evaluation of the eigenvalue functions of the considered system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.295-300
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• 2005

The freeplay, one of the concentrated structural nonlinearities, is inevitable for control surfaces of a real air vehicle due to normal wear of components and manufacturing mismatches. Also aerodynamic nonlinearities caused by a shock wave occur in transonic region. In practice, these nonlinearities induce the limit cycle oscillation (LCO) and decrease the transonic flutter speed. In this study, the fictitious mass method is used to apply a modal approach to nonlinear structural models due to freeplay. The transonic small-disturbance (TSD) equation is used to calculate unsteady aerodynamic forces in transonic region. Nonlinear aeroelastic time responses are predicted by the coupled time integration method (CTIM). This method was also applied to a 3D all-movable control wing to investigate its nonlinear aeroelastic responses. The angle of attack effect on the LCO characteristics has been found to be closely related with the initial pitching moment.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.143-150
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• 2005

In this study, to evaluate the collision behaviors of the navigating vessel and the dolphin protective system protecting the substructures of bridges, the numerical simulation was performed. The analysis model of vessel bow that the plastic deformations are concentrated was composed by shell elements, and the main body of vessel was modeled by beam elements to represent the mass distribution and the change of potential energy. The material model reflecting the confining condition was used for the modeling of the filling soil of dolphin system. The surrounding soil of the dolphin system was modeled as nonlinear springs. As results, it is verified that the dolphin system can adequately dissipate the kinematic energy of the collision vessel. The surrounding soil of the dolphin system is able to resist the collision force of the vessel. And the major energy dissipation mechanism of collision energy is the plastic deformation of the vessel bow and the dolphin system.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.4
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• pp.404-417
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• 2017

The present study numerically analyzed the dynamic behavior of 3D framed structures subject to impulsive slamming forces by violent breaking waves. The structures were modeled using multiple lumped masses for the vertical projections of each member, and the slamming forces from the breaking waves were concentrated on these lumped masses. A numerical algorithm was developed to properly incorporate the slamming forces into a dynamic analysis to numerically determine the structural responses. Then, the validity of the numerical analysis was verified using the results of an existing hydraulic experiment. The numerical and experimental results for various model structures were generally in good agreement. The uncertainties concerning the properties of the breaking waves used in the verification are also discussed here.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1177-1180
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• 2003

Thallium is quantitatively retained by 1,10-phenanthroline and tetraphenylborate onto benzophenone in the pH range 0-11 from a large volumes of aqueous solutions of various samples. After filtration, the solid mass consisting of thallium complex and benzophenone is dissolved with 5 mL of dimethylformamide and the metal was determined by flame atomic absorption spectrometric. About 0.4 ㎍ of thallium can be concentrated from 400 mL of aqueous sample, where its concentration is as low as 1.0 ng/mL. Eight replicate determinations of 8.0 ㎍/mL of thallium in final dimethylformamide solution gave a mean absorbance of 0.160 with a relative standard deviation of 1.7%. The sensitivity for 1% absorption was 0.22 ㎍/mL. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of thallium in various alloys and biological samples.