• Membrane Journal
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• v.27 no.5
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• pp.375-388
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• 2017

Wastewater treatment (WWT) technology has been developing from simple pollutant treatment to energy and resource-saving advanced technology, and various technologies combined with IT and BT are developed to minimize the amount of pollutant and toxic substance discharge to the public water areas and to improve operational efficiency. To examine the development trend of domestic wastewater treatment technology, the registered patent technologies were surveyed, classified and analyzed by year and sector. This paper considers the status of patent registration related to WWT from 2010.1 to 2017.5 in terms of the number of specific technical areas, and the trends are analyzed based on the 10 categorization field such as biological and physicochemical treatment process, equipment and device, material, sludge treatment, membrane, process control and 42 specific technical areas. A total of 3,356 patents have been registered since 2010, and the number of patents has been decreasing since the peak at 2013 and maintains 3~400 per year. The total number of patents has not yet been less than other countries, but the number of patents of more advanced technologies, which can lead the global market, such as process monitoring, new concept processing and equipment technologies is still insufficient compared to developed countries.

• Korean Journal of Materials Research
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• v.9 no.8
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• pp.804-809
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• 1999

Silica films were prepared on Si single crystal substrates by a sol-gel process without DMF using TEOS as a starting material. Films were fabricated by spin coating technique. For films having a composition of TEOS : HCI(1:0.05mol), gelation time, the thickness of films, the formation of cracks and the microstructure of the films were investigated as a function of the molar ratio of $CH_3OH and H_2O$. With 8mol $CH_3OH$, the longest gelation time was measured to be 640hr. The thickness of the coated films was decreased with increasing content of $CH_3OH$. The films were sintered at $500^{\circ}C$ for 1hr with a heating rate of $0.6^{\circ}C$/min. The coated films showed worm-like grains and partially cracked microstructures at an amount of $CH_3OH$ 2mol and 4mol. The addition of more than 8 mole of $CH_2OH$ resulted in crack-free silica films. This suggests that crack-free films can be fabricated by controlling the surface tension energy of the sol solutions without DMF.

• The KIPS Transactions:PartD
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• v.12D no.1 s.97
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• pp.165-178
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• 2005

A product classification scheme is the foundation on which product databases are designed, and plays a central role in almost all aspects of management and use of product information. It needs to meet diverse user views to support efficient and convenient use of product information. It needs to be changed and evolved very often without breaking consistency in the cases of introduction of new products, extinction of existing products, class reorganization, and class specialization. It also needs to be merged and mapped with other classification schemes without information loss when B2B transactions occur. For these requirements, a classification scheme should be so dynamic that it takes in them within right time and cost. The existing classification schemes widely used today such as UNSPSC and eCl@ss, however, have a lot of limitations to meet these requirements for dynamic features of classification. Product information implies a plenty of semantics such as class attributes like material, time, place, etc., and integrity constraints. In this Paper, we analyze the dynamic features of product databases and the limitation of existing code based classification schemes, and describe the semantic classification model proposed in [1], which satisfies the requirements for dynamic features of product databases. It provides a means to explicitly and formally express more semantics for product classes and organizes class relationships into a graph.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.171-181
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• 2020

Recently, free-formed construction technology is becoming a new measure of representing technological superiority and sociocultural ingenuity. However, the CNC processing technology utilizing the existing wood and iron form has limitations in terms of the manufacturing time and material cost. Therefore, in this study, the method and process of manufacturing free-formed EPS form using S-LOM-based 3D printing technology were suggested. Furthermore, through the mock-up test, a comparative analysis of the manufacturing time and precision with CNC milling technology was conducted. The results show that S-LOM-based 3D printing technology has reduced manufacturing time about 57.4% compared to CNC milling technology during the free-formed EPS form manufacturing process. In addition, compared to the design drawings, the maximum error value was 20.5mm, proving the applicability of S-LOM-based 3D printing technology. The results of this study are expected to contribute to the improvement of S-LOM method and the activation of S-LOM method by verifying the applicability of S-LOM-based 3D printing technology.

• The KIPS Transactions:PartA
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• v.12A no.5 s.95
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• pp.461-470
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• 2005

In leaner-controlled environment where learners can decide and restructure the contents, methods and order of learning by themselves, it is possible to apply individualized learning in consideration of each learner's characteristics. The present study analyzed learners' learning path pattern, which is one of learners' characteristics important in Web-based teaching-learning process, using the Apriori algorithm and grouped learners according to their learning path pattern. Based on the result, we designed and implemented a multi-dimensional learning path pattern analysis system to provide individual learners with teaming paths, learning contents, learning media, supplementary teaming contents, the pattern of material presentation, etc. multi-dimensionally. According to the result of surveying satisfaction with the developed system satisfaction with supplementary learning contents was highest (Highly satisfied '$24.5\%$, Satisfied'$35.7\%$). By learners' level, satisfaction was higher in low-level learners (Highly satisfied'$20.2\%$, Satisfied'$31.2\%$) than in high-level learners (Highly satisfied'$18.4\%$, 'Satisfied'$28.54\%$). The developed system is expected to provide learners with multi-dimensionally meaningful information from various angles using OLAP technologies such as drill-up and drill-down.

• Resources Recycling
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• v.12 no.4
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• pp.20-29
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• 2003

In order to efficiently recycle the waste solution resulting from shadow mask processing, nano-sized Ni-ferrite powder was fab-ricated through spray pyrolysis process. The average particle size of the powder was below 100nm. In this study, the effects of the reaction temperature. the concentration of raw material solution and the injection speed of solution on the properties of powder were respectively investigated. As the reaction temperature increased from $800^{\circ}C$ to $1100^{\circ}C$, average particle size of the powder significantly Increased and power structure became more solid, whereat its specific surface area was greatly reduced. Formation rate and crystallization of($NiFe_2$$O_4$) phale increased along with the temperature rise. As the concentrations of iron and nickel components in wastere solution increased, particle size of the powder became larger, particle size distribution became more irregular, and specific surface area was reduced. Formation rate and crystallization of $NiFe_2$$O_4$ phase increased significantly along with the increase of the concentration of solution. As the inlet speed of solution increased, particle size of the powder became larger, particle size distribution became wider, specific surface area was reduced and powder structure became less solid. As the inlet speed of solution decreased, formation rate and crystallization of $NiFe_2$$O_4$ phase significantly increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.651-656
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• 2007

Fish-frames which are left after obtaining fillets or muscle during fish processing, consist of useful food components such as muscle, collagen, calcium, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study was carried out to prepare snack using flatfish frame and also to elucidate food component characterization of the snack. The results of heavy metal and volatile basic nitrogen (VBN) content suggested that flatfish frame was a suitable material for preparing snack. The optimal addition ratio of flatfish frame to mix was 3% for preparing snack according to the results of VBN content, water activity and sensory evaluation. The major fatty acids of the snack with 3% flatfish frame (SFF) were 16:0 and 18:0 as saturates, 18:1n-9+7 as monoenes, and 18:2n-6 and 18:3n-3 as polyenes, while EPA and DHA were contained in small amount SFF. Total amino acid content (9,281.9 mg/100 g) of the SFF was higher than that of the snack without flatfish frame (7,791.3 mg/100 g) and the major amino acids were aspartic acid, glutamic acid, proline and leucine. The calcium and phosphorus contents of SFF were 492.3 mg/100 g and 270.3 mg/100 g, respectively. The Ca/P of SFA was 1.82 which is a good ratio for the absorption of calcium. The SFF was superior in total amino acid, calcium and phosphorus contents compared to the snack without flatfish frame.

• Composites Research
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• v.12 no.5
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• pp.31-39
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• 1999

Glass-fiber reinforced polymeric composites provide the desitable properties of high stiffness and strength as well as specific weight. Hence, they have become some of the most important materials in several industries. These composites can be grouped into thermoplastic and thermoset composites, with thermoplastic composites having several advantages over thermoset composites in mechanical properties and processing. As a result, the study of the material behavior and forming techniques of such composites has attracted considerable attention in recent years. When the continuous fiber-reinforced polymeric composites are molded by flow molding, the molded parts leads to be nonhomogeneity and anisotropic because of the separation and orientation of fibers. As the characteristics of the products are greatly dependent on the separation, it is very important to clarify the separation in relarion to molding conditions, fiber mat structures and mold geometry. In this study, the effects of the mold geometry and the fiber mat structure on the compression moldability are studied using the cup-type molding.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.183-186
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• 1986

To investigate the change of fatty acid content during processing and storage of seafood, the fatty acid contents of 5 kinds of boiled-dried anchovies from the market were quantified using tricosanoic acid (23:0) as an internal standard material. Crude lipid contents of boiled-dried anchovies from the market were $16.9\%$ (Dae-myul), $12.5\%$ (Joong-myul), $9.5\%$ (So-myul), $8.7\%$ (Ja-myul) and $7.6\%$ (Se-myul). Acid value, peroxide value and carbonyl value of boiled-dried anchovies were $14.9{\sim}20.1,\;22.4{\sim}89.8meq/kg$ lipid, and $14.7{\sim}49.6meq/kg$ lipid, respectively. These values were increased as the sample size increased. Total fatty acid content of boiled-dried anchovies were 562.8 (Dae-myul), 572.2 (Joong-myul), 542.8 (So-myul), 587.7 (Ja-myul) and 568.8 (Se-myul) mg/g as 23:0. There was an increasing tendency in the content of 16:0, 16:1 and 18:1, but a decreasing tendency in polyenoic acids such as 20:5 and 22:6 according as the specimen size increased. The major fatty acids of boiled-dried anchovies were 16:0, 16:1, 22:6, 18:1, 20:5 and 14:0.

• Journal of Life Science
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• v.29 no.12
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• pp.1358-1363
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• 2019

In this study, the effect on the free amino acid content and anti-oxidative activity of Arctium lappa samples by heat treatment were compared to obtain data on the conditions required for properly processing the root as a raw material for tea. The results of DPPH and ABTS radical scavenging activity assays showed that 180℃-4 min and 200℃-3 min treatments retained relatively high activity. All heat treatment conditions showed increased polyphenol content compared to the initial sample value of 42.72 mg/l, and the 180℃-4 min and 200-3 min treatments were higher than the others at 60.09 mg/l and 62.74 mg/l, respectively. In the free amino acid analysis of the A. lappa root tea, the tendency of the initial content was confirmed to decrease as temperature and time increased. Changes in phenylalanine, histidine, leucine, and isoleucine were found to be high, while aspartic acid and proline changes were relatively low. Overall, amino acid content decreased significantly under heating conditions above 180℃-3 min and 200℃-2 min. From these results, heat treatment of A. lappa root at 180℃-4 min was deemed optimal based on anti-oxidative activity and free amino acid content.