• Management & Information Systems Review
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• v.37 no.4
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• pp.41-62
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• 2018

As the volume of unstructured data increases through various social media, Internet news articles, and blogs, the importance of text analysis and the studies are increasing. Since text analysis is mostly performed on a specific domain or topic, the importance of constructing and applying a domain-specific dictionary has been increased. The quality of dictionary has a direct impact on the results of the unstructured data analysis and it is much more important since it present a perspective of analysis. In the literature, most studies on text analysis has emphasized the importance of dictionaries to acquire clean and high quality results. However, unfortunately, a rigorous verification of the effects of dictionaries has not been studied, even if it is already known as the most essential factor of text analysis. In this paper, we generate three dictionaries in various ways from 39,800 news articles and analyze and verify the effect each dictionary on the accuracy of document classification by defining the concept of Intrinsic Rate. 1) A batch construction method which is building a dictionary based on the frequency of terms in the entire documents 2) A method of extracting the terms by category and integrating the terms 3) A method of extracting the features according to each category and integrating them. We compared accuracy of three artificial neural network-based document classifiers to evaluate the quality of dictionaries. As a result of the experiment, the accuracy tend to increase when the "Intrinsic Rate" is high and we found the possibility to improve accuracy of document classification by increasing the intrinsic rate of the dictionary.

• Journal of Korean Classical Literature and Education
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• no.15
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• pp.355-387
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• 2008

The purpose of the study was to decide Korean translation and the copying period of "Korean Translation of " and to look all around their characteristics in different versions carefully until now. The "Korean Translation" is a collection of Korean-translated romance and love stories excavated by a professor Kim,Il Geun, and there is not a little meaning in the context of novel history in the point of view of 'Korean translation of a court possession'. Arranging conclusion of the study generally, it is as follows. (1) Considering phonological phenomena, grammar and vocabulary in the study of Korean language, it is presumed that they would be translated into Korean and copied between the regime period of the King Sukjong and the regime period of the King Yungjo in the Joseon Dynasty. For, they were composed of a middle declaration of copied 'Myeoknambon "Korean Translation of Taepyeonggwanggi(태평광기)"' and 'NakseonJaebon(낙선재본)' between the middle of the 17th century and the middle of the 18th century and the regime period of the King Jeongjo in the Joseon Dynasty appointed as the background period of the novels should be excepted. Consequently, through the Korean Translation, we can confirm that the novel scope between the 17th century and the 18th century in Korean novel history was widened until 'The Royal Court' and 'Women'. (2) In the side of vocabulary, the "Korean Translation" also has not a little meaning in the side of a collection translated in the Royal Court. It doesn't have new vocabularies, but partial vocabularies as '(Traces:痕)' '(Clean eyes:明眸)', ' (Sail:帆)', '(Get up:起)', '글이플(Weak grass:弱草)', '쇼록(Owl:? 梟 or 鴉?)', '이 사라심(This life:此生)', and '노혀오매(Look for:訪)' are good data in the study of Korean language. (3) The "Korean Translation" is a valuable data about translation and copying of a court novel and we can discover intentionally changed parts and partially omitted sentences rather in the than in the . There are differences between a translation book and a copying book and we can catch sight of intention of translation and unsettledness of copying in the second work. Therefore, we can know that the "Korean Translation" has a double context which one work is translated and a work in different version is derived, compared to a simple copy. (4) The "Korean Translation" has a close relation with "Hangoldong(閒汨董)", but it doesn't regard the same copy as a foundation. The basic copy of translation of the "Korean Translation" is a different version of the same line as "Hangoldong" and "Jeochobon(저초본:정명기 소장본)" and is more similar line to "Hangoldong", but it is also not the same basic copy. (5) Considering that the "Korean Translation" doesn't has a distinct relation with the "Hangoldong", there is no correlation between the "Korean Translation" and and the "Hangoldong" and . In addition, we could not discover a writer's identity between the two.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.542-547
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• 2021

Glass lined impellers are corrosion resistant to most chemicals, including strong acids, and also have a smooth, non-stick surface, easy to clean and free from impurities in the process. Glass lined home base impeller is a multi-purpose impeller designed to stir a wide viscosity range of liquids from low viscosity fluids to high viscosity fluids, among others, cell culture, yeast culture, and beer fermentation pots, especially used for air-water system breathable stirring. The glass lining for HB impellers, which are simple in structure and competitive in performance, is essential to have upper and lower division in order to make the joint area between the impeller and shaft as small as possible. The upper and lower division of the impeller hardly affects the mixing performance, but the aeration performance. In this study, in order to optimize the shape of the Glass Lining HB impeller, a study was conducted on the effect of the angle between the upper and lower impellers, the clearance between the impellers, and the number of baffles on the aeration power. The optimal shape and baffle plate conditions for the Glass lined HB impeller were derived through the study results that the angle and the clearance between the upper and lower impellers decreased the ration of the power consumption with aeration P_g and that without aeration P₀, P_g/P₀.

• Membrane Journal
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• v.31 no.4
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• pp.253-261
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• 2021

Solutions to water pollution, global warming, and climate change have been currently discussed. Pressure retarded osmosis (PRO) using a difference in salt concentration between two fluids is proposed to meet the demand for clean water and produce eco-friendly energy. Although PRO has been researched continuously, it has not been commercialized yet due to limitations such as lack of technology and the high price of membranes. Meanwhile, the membrane is one of the most significant parts of the PRO engine and salinity gradient power (SGP) technology. Research continues to technologically develop graphene oxide membranes and nanocomposite membranes used in salinity gradient power generation. Studies on efficient membranes, solvents, and solutes are active to enable high energy efficiency of the osmotic heat engine even at low temperatures of waste. Studies have been conducted on reducing internal concentration polarization and increasing power density by using membranes with balanced permeability and selectivity. In this review, dealing with these studies, we discuss the types of PRO membranes, theoretical modeling of technologies through efficient membranes, and other technologies to develop the process efficiency.

• Korean Journal of Optics and Photonics
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• v.32 no.5
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• pp.209-214
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• 2021

High-power continuous-wave operation of a Yb-doped double-clad fiber laser at 1018 nm, pumped by high-power diode lasers at 976 nm, is reported. Based on numerical calculation of the gain and laser signal power along the length of the Yb fiber, it is found that robust operation at 1018 nm can be achieved for a high Yb³⁺-ion excitation density greater than 11.5%, accompanied by high suppression of the feedback from the fiber's end facet. The Yb fiber laser constructed in house yields 626 W of continuous-wave output at 1018 nm for 729 W of incident pump power, corresponding to a slope efficiency of 86.6%. The prospect for power scaling is considered.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.73-73
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• 2019

Angelica gigas Nakai (Korean danggui), a member of the Umbelliferae family, is a Korean traditional medicinal plant whose roots have been used for treating gynecological diseases. Transcriptomics is the study of the transcriptome, which is the complete set of RNA transcripts that are produced by the genome, using high-throughput methods, such as microarray analysis. In this study, transcriptome analysis of A.gigas Nakai was carried out. Transcriptome sequencing and assembly was carried out by using Illumina Hiseq 2500, Velvet and Oases. A total of 109,591,555 clean reads of A. gigas Nakai was obtained after trimming adaptors. The obtained reads were assembled with an average length of 1,154 bp, a maximum length of 13,166 bp, a minimum length of 200 pb, and N50 of 1,635 bp. Functional annotation and classification was performed using NCBI NR, InterprotScan, KOG, KEGG and GO. Candidate genes for phenylpropanoid biosynthesis were obtanied from A.gigas transcriptome and the genes and its proteins were confirmed through the NCBI homology BLAST searches, revealing high identity with other othologous genes and proteins from various plants pecies. In RNA sequencing analysis using an Illumina Next-Seq2500 sequencer, we identified a total 94,930 transcripts and annotated 71,281 transcripts, which provide basic information for further research in A.gigas Nakai. Our transcriptome data reveal that several differentially expressed genes related to flower color in A.gigas Nakai. The results of this research provide comprehensive information on the A.gigas Nakai genome and enhance our understanding of the flower color related gene pathways in this plant.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.85-99
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• 2022

Recently, environmental issues have become serious, and Jeju Island is promoting a pilot project of a smart collection system(waste weight-based collection system) at clean houses in Yongdam 1-dong. However, the new system faced an opposition from elderly residents who were not accustomed to using machines or smart devices. In order to solve this problem, it was intended to suggest policies related to this by conducting environmental education and identifying problems with the effect of environmental education awareness through data analysis method. The results showed positive answers in most of the satisfaction and achievement evaluations, but it is also true that most of the residents need to be educated and more information should be given. In order to vitalize education, it is important to increase the number of instructors and support them to increase their expertise. It is also important to take a practical process that strengthens public relations, shares information, and links with the local community to increase the actual participation of local residents. In addition, it is critical to secure a budget from local governments to maintain education and public awareness, and it will be helpful to link with talent donation projects in the region.

• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.81-89
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• 2021

In recent years, the design of buildings is changing from formal to creative and freeform. Accordingly, the scale of construction technology is changing to architectural design and construction of irregular buildings. Using the FDM method, which is one of the 3D printing technologies, it is possible to manufacture various forms of irregular formwork inexpensively and quickly coMPared to the existing formwork, and it seems to be able to solve the manpower problem. Using a 3D printer, the PLA filament formwork is produced in the form of a cylinder and a rectangular cuboid, and the usability of the PLA filament formwork is confirmed by examining the compression strength test and the degree of deformation and reusability over 28 days of age. Different sizes of additional specimens are also conducted according to the size. As a result of the experiment, it was confirmed that the filament formwork itself has about 3~4MPa strength. As a result of reviewing data through existing linear studies and experiments, it is appropriate to use more than 60% infill, and it is advantageous in terms of strength. As a result of cutting and dismantling the filament formwork, the surface is very clean and there is no damage, so it can be reused.

• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.105-111
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• 2011

The purpose of this study was to find out the effect of a torrent control structure using customized tetrapods on the forest water quality conservation and management. The study was conducted in the Honggye valley located in Sanchung-gun, Gyungsangnam-do, and stream water quality was compared before and after construction of torrent control structure. After construction of the torrent control structure using customized tetrapods, pH of stream water didn't get out of the range of River water quality standard class I. After construction of the torrent control structure using customized tetrapods, Dissolved Oxygen concentration didn't change, and Electrical Conductivity measurements agreed well within the range of normal clean stream water quality. After construction of the torrent control structure using customized tetrapods, average of total amount of anion was 3.07/2.30~3.60 mg/L, being slightly greater than before construction. Stream water quality after construction of the torrent control structure was similar to before construction. Therefore, it was find out that the torrent control structure didn't affect stream water quality.