• Clean Technology
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• v.27 no.3
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• pp.232-239
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• 2021

In order to develop a novel system named "thermal medium and gas circulation type pyrolysis system," this study was conducted to obtain basic data for process simulation before performing the pyrolysis experiment. Polypropylene (PP) was chosen as model material in the basic pyrolysis experiment instead of waste plastic and fluidized sand (hereinafter referred to as "sand"), and it was used as a heat transfer material in the "thermal medium and gas circulation type pyrolysis system." Ni was impregnated as an active catalyst on the sand to promote catalytic pyrolysis. The basic physical properties of PP were analyzed using a thermogravimetric analyzer, and pyrolysis was performed at 600 ℃ in an N₂ atmosphere to produce liquid oil. The distribution of the carbon number of the liquid oil generated through the catalytic pyrolysis reaction was analyzed using GC/MS. We investigated the effects of varying the pyrolysis space velocity and catalyst amount on the yield of liquid oil and the carbon number distribution of the liquid oil. Using Ni/sand, the yield of liquid oil was increased except with the pyrolysis condition of 10 wt% Ni/sand at a space velocity of 30,000 h^-1, and the composition of C₆ ~ C₁₂ hydrocarbons increased. With increases in the space velocity, higher yields of liquid oil were obtained, but the composition of C₆ ~ C₁₂ hydrocarbons was reduced. With 1 wt% Ni/sand, the oil yield obtained was greater than that obtained with 10 wt% Ni/sand. In summary, when 1 wt% Ni/sand was used at a space velocity of 10,000 h^-1, the oil yield was 60.99 wt% and the composition of C₆ ~ C₁₂ hydrocarbons was highest at 42.06 area%.

• Journal of Intelligence and Information Systems
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• v.27 no.3
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• pp.175-197
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• 2021

Recently, with the development of deep learning technology, research on unstructured data analysis is being actively conducted, and it is showing remarkable results in various fields such as classification, summary, and generation. Among various text analysis fields, text classification is the most widely used technology in academia and industry. Text classification includes binary class classification with one label among two classes, multi-class classification with one label among several classes, and multi-label classification with multiple labels among several classes. In particular, multi-label classification requires a different training method from binary class classification and multi-class classification because of the characteristic of having multiple labels. In addition, since the number of labels to be predicted increases as the number of labels and classes increases, there is a limitation in that performance improvement is difficult due to an increase in prediction difficulty. To overcome these limitations, (i) compressing the initially given high-dimensional label space into a low-dimensional latent label space, (ii) after performing training to predict the compressed label, (iii) restoring the predicted label to the high-dimensional original label space, research on label embedding is being actively conducted. Typical label embedding techniques include Principal Label Space Transformation (PLST), Multi-Label Classification via Boolean Matrix Decomposition (MLC-BMaD), and Bayesian Multi-Label Compressed Sensing (BML-CS). However, since these techniques consider only the linear relationship between labels or compress the labels by random transformation, it is difficult to understand the non-linear relationship between labels, so there is a limitation in that it is not possible to create a latent label space sufficiently containing the information of the original label. Recently, there have been increasing attempts to improve performance by applying deep learning technology to label embedding. Label embedding using an autoencoder, a deep learning model that is effective for data compression and restoration, is representative. However, the traditional autoencoder-based label embedding has a limitation in that a large amount of information loss occurs when compressing a high-dimensional label space having a myriad of classes into a low-dimensional latent label space. This can be found in the gradient loss problem that occurs in the backpropagation process of learning. To solve this problem, skip connection was devised, and by adding the input of the layer to the output to prevent gradient loss during backpropagation, efficient learning is possible even when the layer is deep. Skip connection is mainly used for image feature extraction in convolutional neural networks, but studies using skip connection in autoencoder or label embedding process are still lacking. Therefore, in this study, we propose an autoencoder-based label embedding methodology in which skip connections are added to each of the encoder and decoder to form a low-dimensional latent label space that reflects the information of the high-dimensional label space well. In addition, the proposed methodology was applied to actual paper keywords to derive the high-dimensional keyword label space and the low-dimensional latent label space. Using this, we conducted an experiment to predict the compressed keyword vector existing in the latent label space from the paper abstract and to evaluate the multi-label classification by restoring the predicted keyword vector back to the original label space. As a result, the accuracy, precision, recall, and F1 score used as performance indicators showed far superior performance in multi-label classification based on the proposed methodology compared to traditional multi-label classification methods. This can be seen that the low-dimensional latent label space derived through the proposed methodology well reflected the information of the high-dimensional label space, which ultimately led to the improvement of the performance of the multi-label classification itself. In addition, the utility of the proposed methodology was identified by comparing the performance of the proposed methodology according to the domain characteristics and the number of dimensions of the latent label space.

• Journal of the Korean Wood Science and Technology
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• v.49 no.1
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• pp.23-43
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• 2021

In this study, we selected two essential oils, Citrus unshiu and Cinnamomum cassia with superior antioxidant effects from the essential oils of 7 wild plants in South Korea and examined their antimicrobial activity against Candida albicans, which causes dermatitis to identify the antimicrobial components in the essential oils. As a result of measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, SC50 value of the Citrus unshiu essential oil was 0.010 mg/mL, while for the Cinnamomum cassia essential oil, SC50 value was 0.09 mg/mL. In addition, when ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was measured, SC50 value of the Citrus unshiu essential oil was 0.09 mg/mL, while for the Cinnamomum cassia essential oil, it was 0.06 mg/mL, exhibiting high antioxidant activity. For the minimum inhibitory concentration (MIC), the essential oil of Cinnamomum cassia was 1.25 mg/mL and that of Citrus unshiu was 5 mg/mL, demonstrating a high antimicrobial activity of the Cinnamomum cassia essential oil. Through the thin layer chromatography (TLC) bioassay, we assessed the antimicrobial activity against C. albicans according to the fraction components of the two essential oils. Also, by using preparative TLC (prep. TLC), we obtained the active fractions, and by performing GC/MS analysis of the components with the same Rf value, we identified the antimicrobial-active components. As a result, the main components having antioxidant and antimicrobial activities were cinnamyl acetate, eucalyptol, linalool, and citral of the Cinnamomum cassia essential oil and linalool from the Citrus unshiu essential oil. Also, based on the analysis of the fractional components that showed antioxidant and antimicrobial activities in both of the two essential oils, it was found that linalool has antioxidant activity, while cinnamyl acetate, eucalyptol, citral, and geranyl acetate have antioxidant and antimicrobial activities.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.63-70
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• 2021

Radiographic contrast agents are used for diagnostic purposes and are one of the factors affecting measured values in bone density tests. They are absorbed into tissues and have an effect of increasing the measured values of bone density, so they are avoided as much as possible before performing a bone density test. MRI contrast agents, which have different physical properties and mechanisms of action than radiographic contrast agents, are based on gadolinium, a metal element. They have radiopacity characteristics, so MRI are generally performed prior to examination using radiation. The purpose of this study was to investigate the effects of MRI contrast agents on bone mineral density examination using dual energy X-ray absorption. Two types of gadolinium based MRI contrast agents were injected into an acrylic water tank for each volume, and the humanoid spine phantom was inserted and the BMD and T-score from (L1-L4) were analyzed by scanning a total of 30 times, 5 times for each injection type. The average value of the measured total (L1-L4) bone density for each of the two contrast agents was 0.952±0.052, 0.957±0.050, and 0.956±0.05g/㎠, respectively, for the Gadoterate Meglumine component 0mL, 7.5mL and 15mL, when the gadobutrol components were 0mL, 5mL, and 10mL, there was no statistically significant difference at all sites at 0.953±0.001, 0.954±0.001, and 0.945±0.001g/㎠, respectively(p>0.05). The average value of total T-score was -0.46±0.05, -0.4±0, -0.42±0.04 when the Gadoterate Meglumine component was 0mL, 7.5mL and 15mL, respectively. When the Gadobutrol ingredients were 0mL, 5mL and 10mL, there was no statistically significant difference in all areas, with -0.46±0.05, -0.46±0.05, and 0.5±0.00, respectively. In this experiment, the MRI contrast agent was found to have no effect on bone density tests, using the dual-energy X-ray absorption method. There is a limitation in that physical conditions such as kidney and health conditions etc. were not taken into consideration, so further clinical research is expected to be conducted in the future.

• Research in Plant Disease
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• v.26 no.4
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• pp.264-271
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• 2020

We have developed a simultaneous diagnostic method that can identify both the species of thrips and tomato spotted wilt virus (TSWV) that are problematic in chrysanthemum plants. This is a method of amplifying DNA by performing reverse transcription-polymerase chain reaction by simultaneously adding primers specific to TSWV coat protein (N) gene and primers specific to the internal transcribed spacer 2 region of Frankliniella occidentalis and F. intonsa using total nucleic acid extracted from one thrips. The sizes of DNA fragments for TSWV, F. occidentalis, and F. intonsa were 777, 287, and 367 bp, respectively. These results showed species identification of thrips and whether thrips carrying TSWV can be simultaneously confirmed. Further usefulness of the simultaneous diagnostic method was made from greenhouse survey at chrysanthemum greenhouses in Taean (Chungcheongnam-do) and Changwon (Gyeongsangnam-do) to investigate the identification of thrips species and the rate of thrips carrying TSWV. Of thrips collected from the greenhouses, 83.7% thrips was F. occidentalis and 72.9% F. occidentalis carried TSWV in Taean. Similarly, the diagnostic method showed that 92.2% thrips was F. occidentalis and 84.0% F. occidentalis carried TSWV in Changwon. These results confirm that F. occidentalis is a dominant thrips species and the thrips species plays a crucial role in the transmission of TSWV in chrysanthemum plants in the greenhouses. Taken together, this study showed a simple diagnostic method for thrips identification and epidemiological studies of the timing and spread of TSWV through thrips in chrysanthemum greenhouses in South Korea.

• (The) Research of the performance art and culture
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• no.32
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• pp.171-208
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• 2016

Female folk song singers do not necessarily recognize the indigenous elements, which are, however, naturally reflected in the narration in the context. Singers of Taebaek Ararei recognize the dialect, the tone and the song when performing. Traditional Ararei had been performed by singers in the village of slash-and-burn field in Hwangji. Cheolam and Jangseong do not have their own traditional songs sing they are mining regions but had adopted songs from other areas including Gyeonggbuk, which still remain as alternative versions. Many elements of Jeongseon Arari and Samcheok Menari are in the narration and the songs. In terms of the context, alternative versions of Ararei are old Arirang melodies from slash-and-burn fields and were confirmed to be a very old form of oral folk songs in Gangwondo. Female singers of 3 generations, Hwaok Mun, Geumsu Kim and Hyojeong Kim, who keep the tradition and identity of Taebaek Ararei, show the integration of the past, present and future of Ararei. The Ararei Preservation Society continuously organizes singers' performances and maintains the tradition. The singer Hwaok Mun was born in Taecheon, Pyeongannamdo and moved to south at 5 and lived in Hajang, Samcheok and then moved to Jangseong and lived in Jaemungok. She is a mother of 6 children and has been a farmer for most of her life. She currently resides in Mungokdong and would sing Ararei at village feasts or events. She says she learned the song naturally because Ararei was sung very often in the past around Taebaek area. She is a typical native Arirang singer. The singer Geumsu Kim is a daughter of Hwaok Mun and leads the Taebaek Ararei Preservation Society to study, maintain and introduce the sound of Taebaek(Taebaek Arirang). She introduces Miner Arirang and Taebaek Ararei to the society members and the local residents. The singer Hyojeong Kim is a granddaughter of Hwaok Mun and follows the tradition of her grandmother and mother while adopting more modern Arirang contents.

• (The) Research of the performance art and culture
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• no.35
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• pp.405-439
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• 2017

In this article, I suggest issues and tasks in transmission of Gyeonggi Province folk songs after thorough study of designation of Gyeonggi Province folk songs as intangible cultural asset, reproduction and transmission. Intangible cultural assets are classified into seasonal playing and songs. Originally, category or extension of folk songs is above mere songs and it also embraces personal lives as well as village communities. Intangible assets of folk songs are folk art, group events and non-stage events at the same time based on tradition, history, uniqueness, characters of field value. Gyeonggi Province has 9 intangible assets now because of the revocation of several assets (All Gyeonggi Province, Hwasung, Gwacheon) within five years after initial designation of 13 assets in 1998. They are mostly distributed in the north Gyeonggi region where is close to the DMZ and delay in development seems to have enabled the preservation. Most of the intangible cultural assets are farming songs and weeding which show characteristics of Gyeonggi Province. Most of the designees are who performed excavation, recovery, excluding a few cases without designees on designation, and almost all the designee passed away. Number of cases have been revoked because transmission was not completed or some cases were transmitted to groups rather than specific designees. Subscription concert, the biggest and most representative event, is performed once a year with all of the 9 intangible cultural assets in the original complete forms of the designation. Intangible cultural assets are classified into seasonal playing and songs. In general, current performance of the intangible cultural assets and folk songs are same as the originally designated forms and are not in varied forms other than folk songs like songs for rice-planting and weeding. Funeral songs are transmitted in Yangju and Yangpyeong. In terms of the operation, preservation societies having training centers have been performing more constant activities for preservation including lecture, performance and transmission. Members are quite aged and the societies are suffering from lack of support fund for reproduction and transmission. Problems in reproduction and tasks for the transmission I would like to suggest are like followings. First, preservation and value of the cultural assets. Second, new understanding of designation and revocation of the intangible cultural assets. Third, record of performance and sound source. Fourth, liaison with local communities. Fifth, organization of professional resources and establishment of systematic support and management.

• (The) Research of the performance art and culture
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• no.33
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• pp.129-163
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• 2016

This study examines processes of cultural introductions and transformations among Korea, China and Japan via focuses on the formative characteristics of nasori(納曾利) masks belonging to komagaku (高麗樂), part of bugaku (舞樂), a Japanese court dance and music. Previous studies of traditional masks in East Asia focus on their dramatic characters and entertaining aspects. On the contrary, it approaches to their origins through the formative characteristics of komagaku nasori masks. Prince of Lanling, the representative togaku passed to Japan, and komagaku nasori perform a pair of toubu (答舞). One formative characteristic between Prince of Lanling and nasori masks is a dangling jaw (吊り顎). Masks having 'he' (へ)-shaped eyes like Japan's okina (翁) masks are characterized by a division (切顎) between the face and jaw, which is as same as the Korean masks. Other common grounds between Prince of Lanling and nasori masks are grotesque ghost faces and concentric double-circled eyes with their outlines painted gold. Concentric double-circled eyes prove that they spread to broader areas before the age of togaku and developed into a variety of divine-animal mask patterns. That Korean masks and nasori masks both have concentric double-circled eyes and dangling jaws is a significant starting point in studying the origin of traditional performing art in East Asia. Japan's bugaku has been passed down in shrines as part of folk religion. However, there exist in Korea no records or examples related to komagaku nasori masks introduced to Japan. This study provides some clues to comparison between Korean masks and komagaku nasori masks by focusing on the formative characteristics of the latter. The researcher suggests a new perspective to nasori mask dance by re-examining earlier Korean studies of the introduction of Daemyeonmu of Prince of Lanling to Japan through Shilla and the assumption of Nasori as Shilla music.

• Korean Journal of Comparative Education
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• v.26 no.3
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• pp.103-132
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• 2016

This study aims to suggest ways of improving the quality of confirmation hearings for the Secretary of Education in South Korea by: 1) comparing the confirmation process by the presidents in South Korea and the United States; and 2) contrasting procedures and contents of hearings for Education Secretary nominee in South Korea and the United States. As the process of selecting a nominee to be the Secretary of Education started, the Blue House Office of Secretary conducted an investigation on the nominee's personal details, family matters, and etc within a week. The investigation, with very limited time frame, led the selection process to be a mere verification on the nominee's morality. On the other hand, the White House Office of Presidential Personnel carried out a thorough investigation on the nominee collectively with the White House Council, Federal Bureau of Investigation (FBI), and Internal Revenue Service, taking from two to three months. In terms of contents of the hearings, the members of the ruling party mainly asked the nominee for clarification, and his ideas on certain policies, whereas the opposition party focused mostly on verifying his morality. In addition, the committee members led the hearing whilst strongly expressing their own political ideologies. However, in the case of the hearings in the United States, the committee members did not ask any questions to verify the nominee's morality but questions that could help them to get an understanding of the nominee's experience, professionalism, and perspective on nation- wide issues regarding education and federal education policy. As for the procedural characteristics of South Korean hearings, the Committee on Education conducted the hearing with a week of advanced preparation. However, submission of required reports by the nominee, performing confirmation hearings, and reports on the hearing were not mandatory in order to appoint the nominee as the Secretary of Education. On the contrary, in the United States, the members of the Committee on Health, Education, Labor, and Pension spent about a month preparing for the confirmation hearing. For the nominee to be appointed, submission of reports and the committee's approval on the President's nomination were required. Based on the results, this research suggests that it is important to develop a policy that can strengthen the substantiality of the nomination process, to establish a professional agency for personnel investigation, to make a mandatory submission of personal reports before hearings, to extend the time frame for hearing preparation, to secure enough time slot for nominees to respond, and to increase the member's autonomy.

• (The) Research of the performance art and culture
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• no.34
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• pp.111-131
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• 2017

Korean Shamanism has long been regarded as the peripheral cult or supersition by the majoriy of the society. This fact is a result by the influence of the mass media, especially the motion pictures, which intentionally reflected the negative images of the Shamanism. The documentary films, which stress the objectivity and the reality, rather disclose the neutral position toward the Shamanism. In fact, the directors of the documentary films who have more or less close relationship with the Shamanism have tried to exhibit the mental world and the traditionality of the Shamanism. In this paper, I will explore the value of Shamanism reflected in the documentary films. I focus of two films; directed by the Korean and directed by a foreigner. In this way, I can compare the attitudes of the two directors toward the Korean Shamanism. The director of confessed that he was attracted by the aspect of a musical underlied in the shaman ritual. However, the film does not show the artistic beauty of the shaman music because the director failed to understand the essential aspect of the shaman ritual, that is, the music. In this way, the director failed to show the distinct characteristics of the shamanism to the audience. The director of , a music herself, was focused on the music of the shamanism. The story flows to the adventure to seek a "master" with a long journey to enjoy diverse genres of Korean performing arts. This story resembles the epic shaman song, the Princess Bari. In this way, the audience can easily grasp the beauty of Korean culture. Music is said to be a universal language and, at the same time, a non-universal language which reflects a special trait of a cultural community. The Korean shaman ritual music is a non-universal language that is an accumulation of the Korean culture for a long time. The Korean director fails to exhibit the essential characteristics of the Shamanism since he does not have enough knowledge toward the shaman ritual music in . However, the foreign director, who is a music herself, successively disclose the underlying beauty of Korean shaman ritual music and Korean traditional culture in .