• Journal of dental hygiene science
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• v.18 no.6
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• pp.340-348
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• 2018

The purpose of this study was to examine the perceptions, precedent tasks, positive and negative effects, and expandable professional tasks regarding the inclusion of dental hygienists (DHs) in the category of medical personnel. This study involved a survey of 259 DHs and 128 dentists. The findings were as follows: 94.2% of DHs and 46.9% of dentists were aware of inclusion in the category of medical personnel; 95.0% of DHs and 64.1% of dentists supported the idea; and 84.9% of DHs and 51.6% of dentists recognized its legitimacy. As for precedent tasks for inclusion in the category of medical personnel, both DHs and dentists scored high points in professional consciousness in the area of occupation. Both DHs and dentists scored the highest points in the quality management of DH education and the lowest points in the unification of school systems in the area of institution. In the area of society, DHs scored high points in the persuasion of the central government, whereas dentists scored high points in collaboration among concerned organizations. Regarding the positive effects of inclusion in the category of medical personnel, both DHs and dentists scored the highest points in the expanded perception of DHs. As for its negative effects, DHs scored high points in the aggravation of salary increase, whereas dentists scored high points in the aggravation of salary increase. Regarding expandable professional tasks after the inclusion of DHs in the category of medical personnel, the management of independent periodontal care programs recorded the highest percentage both in DHs and dentists. These findings highlight the need for adequate discussions about the meanings of the inclusion of DHs in the category of medical personnel and will hopefully contribute to the rational adjustment and legalization of DHs' works with regard to their inclusion in the category of medical personnel.

• Korean Journal of Environment and Ecology
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• v.33 no.1
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• pp.9-15
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• 2019

Artiodactyla, which is an even-toed mammal, widely inhabits worldwide. In recent years, wild Artiodactyla species have attracted public attention due to the rapid increase of crop damage and road-kill caused by wild Artiodactyla such as water deer and wild boar and the decrease of some species such as long-tailed goral and musk deer. In spite of such public attention, however, there have been few studies on Artiodactyla in Korea, and no studies have focused on the trend analysis of Artiodactyla, making it difficult to understand actual problems. Many recent studies on trend used text-mining and co-occurrence analysis to increase objectivity in the classification of research subjects by extracting keywords appearing in literature and quantifying relevance between words. In this study, we analyzed texts from research articles of three countries (Korea, China, and Japan) through text-mining and co-occurrence analysis and compared the research subjects in each country. We extracted 199 words from 665 articles related to Artiodactyla of three countries through text-mining. Three word-clusters were formed as a result of co-occurrence analysis on extracted words. We determined that cluster1 was related to "habitat condition and ecology", cluster2 was related to "disease" and cluster3 was related to "conservation genetics and molecular ecology". The results of comparing the rates of occurrence of each word clusters in each country showed that they were relatively even in China and Japan whereas Korea had a prevailing rate (69%) of cluster2 related to "disease". In the regression analysis on the number of words per year in each cluster, the number of words in both China and Japan increased evenly by year in each cluster while the rate of increase of cluster2 was five times more than the other clusters in Korea. The results indicate that Korean researches on Artiodactyla tended to focus on diseases more than those in China and Japan, and few researchers considered other subjects including habitat characteristics, behavior and molecular ecology. In order to control the damage caused by Artiodactyla and to establish a reasonable policy for the protection of endangered species, it is necessary to accumulate basic ecological data by conducting researches on wild Artiodactyla more.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.985-994
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• 2018

Bio-heavy oil for power generation is a product made by mixing animal fat, vegetable oil and fatty acid methyl ester or its residues and is being used as steam heavy fuel(B-C) for power generation in Korea. However, if the fuel supply system of the fuel pump, the flow pump, the injector, etc., which is transferred to the boiler of the generator due to the composition of the raw material of the bio-heavy oi, causes abrasive wear, it can cause serious damage. Therefore, this study evaluates the fuel characteristics and lubricity properties of various raw materials of bio-heavy oil for power generation, and suggests fuel composition of biofuel for power generation to reduce frictional wear of generator. The average value of lubricity (HFRR abrasion) for bio-heavy oil feedstocks for power generation is $137{\mu}m$, and it varies from $60{\mu}m$ to $214{\mu}m$ depending on the raw materials. The order of lubricity is Oleo pitch> BD pitch> CNSL> Animal fat> RBDPO> PAO> Dark oil> Food waste oil. The average lubricity for the five bio-heavy oil samples is $151{\mu}m$ and the distribution is $101{\mu}m$ to $185{\mu}m$. The order of lubricity is Fuel 1> Fuel 3> Fuel 4> Fuel 2> Fuel 5. Bio-heavy oil samples (average $151{\mu}m$) show lower lubricity than heavy oil C ($128{\mu}m$). It is believed that bio-heavy oil for power generation is composed of fatty acid material, which is lower in paraffin and aromatics content than heavy oil(B-C) and has a low viscosity and high acid value, resulting in inhibition of the formation of lubricating film by acidic component. Therefore, in order to reduce friction and abrasion, it is expected to increase the lubrication of fuel when it contains more than 60% Oleo pitch and BD pitch as raw materials of bio-heavy oil for power generation.

• Journal of dental hygiene science
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• v.18 no.6
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• pp.380-388
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• 2018

This research team extracted keywords from 953 papers published in the Journal of Dental Hygiene Science from 2001 to 2018 for keyword and centrality analyses using the Keyword Network Analysis method. Data were analyzed using Excel 2016 and NetMiner Version 4.4.1. By conducting a deeper analysis between keywords by overall keyword and time frame, we arrived at the following conclusions. For the 17 years considered for this study, the most frequently used words in a dental science paper were "Health," "Oral," "Hygiene," and "Hygienist." The words that form the center by connecting major words in the Journal of Dental Hygiene through the upper-degree centrality words were "Health," "Dental," "Oral," "Hygiene," and "Hygienist." The upper betweenness centrality words were "Dental," "Health," "Oral," "Hygiene," and "Student." Analysis results of the degree centrality words per period revealed "Health" (0.227), "Dental" (0.136), and "Hygiene" (0.136) for period 1; "Health" (0.242), "Dental" (0.177), and "Hygiene" (0.113) for period 2; "Health" (0.200), "Dental" (0.176), and "Oral" (0.082) for period 3; and "Dental" (0.235), "Health" (0.206), and "Oral" (0.147) for period 4. Analysis results of the betweenness centrality words per period revealed "Oral" (0.281) and "Health" (0.199) for period 1; "Dental" (0.205) and "Health" (0.169) for period 2, with the weight then dispersing to "Hygiene" (0.112), "Hygienist" (0.054), and "Oral" (0.053); "Health" (0.258) and "Dental" (0.246) for period 3; and "Oral" (0.364), "Health" (0.353), and "Dental" (0.333) for period 4. Based on the above results, we hope that further studies will be conducted in the future with diverse study subjects.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.834-846
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• 2017

An increase in the number of retiring experienced pilots as well as drastic graying of new pilots will raise the problems on deepening imbalance of supply and demand of pilots over the next 7 years, which could entail fatal problems for the safety of harbour pilotage. In this study, the improvement plan of legal system to ease imbalance between supply and demand of pilots and help secure more experienced pilots has been proposed. A current state survey and analysis, statistical analysis, questionnaire survey on foreign countries, in-depth consultation with experts, etc., were all carried out to support this research. The conclusions of this study are, firstly, to propose an amendment that the minimum requirement of 5 years of seagoing service as a master to sit for the pilot exam should be relaxed to 2 years(which must include at least 1 year of master's seagoing service within the most recent 5 years) but the minimum requirement of 1 year of pilotage service should be reinforced to 1 year and 6 months to obtain a higher class of pilot certificate. Secondly, it is proposed that an amendment offering an additional 1 point per year over the minimum period of 2 years of seagoing service as a master should be added, with a maximum of 10 points in order to rationalize the additional incentive point system. In order to secure experienced pilots and resolve the legal conflict between the certificate revalidation system and the retirement system, it is also proposed that an amendment be passed revoking the retirement system and limiting the validity of any new certificates only to 68 years of age when issuing or revalidating a certificate, if an applicant is over a certain age. Promotional work, such as collecting opinions from interested parties and generating positive public awareness, should be carried out in the future. It will also be necessary to conduct a study on the training pilot exam system.

• Korean Journal of Environment and Ecology
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• v.33 no.3
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• pp.303-320
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• 2019

Plants interact with various biotic and abiotic environmental factors. It requires much information to understand the traits of a plant species. A shortage of information would restrict the assessment, especially in the evaluation of what kind of factors influence a plant species to face extinction. Polygonatum stenophyllum Maxim. is one of the northern plants of which Korea is the southern distribution edge. The Korean Ministry of Environment had designated it to be the endangered species until December 2015. Although it is comparatively widespread, and a large population has recently been reported, it is assessed to be vulnerable due to the low population genetic diversity. This study evaluated the current distribution of Polygonatum stenophyllum Maxim. We investigated the vegetational environment, population structures, phenology, soil environment, and self-incompatibility based on the results. Lastly, we evaluated the current threats observed in the habitats. The habitats tended to be located in the areas where the masses at the edge of the stream accumulated except for those that were located on slopes of some mountainous areas. Most of them showed a stable population structure and had re-established or recruited seedlings. Polygonatum stenophyllum Maxim. had the difference in time when the shoots appeared above the ground depending on the depth of the rhizome located in the underground. In particular, the seedlings and juveniles had their rhizome located shallow in the soil. Visits by pollinator insects and success in pollination were crucial factors for bearing of fruits by Polygonatum stenophyllum Maxim. The threats observed in the habitat of Polygonatum stenophyllum Maxim. included the expansion of cultivated land, construction of new buildings, and construction of river banks and roads. Despite such observed risk factors, it is not likely that there would be rapid population reduction or extinction because of its widespread distribution with the total population of more than 2.7 million individuals and the new populations established by the re-colonization.

• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.240-255
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• 2016

In many cities in the East and West during the modern period, historical resources were perceived as obstacles to urban development and were treated as deficiencies calling for development. Korea underwent a process of drastic urbanization and industrialization almost unprecedented in modern history. In this process of turmoil, cities expanded rapidly and went through a series of changes. City development followed a repeated cycle in which resources were concentrated in the city area, which, in turn, led to further development. However, such method of development is reaching its limits. In order to make a city desirable for living, it is crucial to make an effort to build a sustainable city environment where life and history coexist harmoniously. It is now time to consider how to carry forth sustainable development in the city where the past, present, and future coexist. If so, how will the future of our cities look and the form of housing change? To answer this question, we examined Urban Hanok Residential Areas and Hanyangdoseong neighborhood village, which went through rapid changes in the modern period. The Hanok, which was a commonplace sight in the past, has been perceived as an underdeveloped form of housing, easily targeted for redevelopment only a few years ago; so was the case with Hanyangdoseong neighborhood village. Yet now these are being revalued as sustainable housing areas able to coexist with the history of the city. That is, through restoration, their potential of contributing to the history and identity of the city is gaining recognition. In this regard, it holds great implications for us to look at the changes that traditional Korean housing areas and castle villages have undergone.

• Phonetics and Speech Sciences
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• v.11 no.1
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• pp.29-40
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• 2019

The paper investigates the minimal pair of Korean phonemes quantitatively. To achieve this goal, I calculated the number of consonant minimal pairs in the syllable-initial position as both raw counts and relative counts, and analyzed the part of speech relations of the two words in the minimal pair. "Urimalsaem" was chosen as the object of this study because it was judged that the minimal pair analysis should be done through a dictionary and it is the largest among Korean dictionaries. The results of the study are summarized as follows. First, there were 153 types of minimal pairs out of 337,135 examples. The ranking of phoneme pairs from highest to lowest was 'ㅅ-ㅈ, ㄱ-ㅅ, ㄱ-ㅈ, ㄱ-ㅂ, ㄱ-ㅎ, ${\ldots}$, ㅆ-ㅋ, ㄸ-ㅋ, ㅉ-ㅋ, ㄹ-ㅃ, ㅃ-ㅋ'. The phonemes that played a major role in the formation of the minimal pair were /ㄱ, ㅅ, ㅈ, ㅂ, ㅊ/, in that order, which showed a high proportion of palatals. The correlation between the raw count of minimal pairs and the relative count of minimal pairs was found to be quite high r=0.937. Second, 87.91% of the minimal pairs shared the part of speech (same syntactic category). The most frequently observed type has been 'noun-noun' pair (70.25%), and 'vowel-vowel' pair (14.77%) was the next ranking. It can be indicated that the minimal pair could be grouped into similar categories in terms of semantics. The results of this study can be useful for various research in Korean linguistics, speech-language pathology, language education, language acquisition, speech synthesis, and artificial intelligence-machine learning as basic data related to Korean phonemes.

• Journal of Life Science
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• v.29 no.5
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• pp.537-544
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• 2019

Genome editing technology employing gene scissors has generated interest in molecular breeding in various fields, and the development of the third-generation gene scissors of the clustered, regularly interspaced short palindromic repeat (CRISPR) system has accelerated the field of molecular breeding through genome editing. In this study, we analyzed the possibility of silkworm molecular breeding using gene scissors by genomic and phenotypic analysis after editing the biogenesis of lysosome-related organelles (BmBLOS) gene of Bakokjam using the CRISPR/Cas9 system. Three types of guide RNAs (gRNA) were synthesized based on the BmBLOS gene sequence of Bakokjam. Complexes of the prepared gRNA and Cas9 protein were formed and introduced into Bombyx mori BM-N cells by electroporation. Analysis of the gene editing efficiency by T7 endonuclease I analysis revealed that the B4N gRNA showed the best efficiency. The silkworm genome was edited by microinjecting the Cas9/B4N gRNA complex into silkworm early embryos and raising the silkworms after hatching. The hatching rate was as low as 18%, but the incidence of mutation was over 40%. In addition, phenotypic changes were observed in about 70% of the G0 generation silkworms. Sequence analysis showed that the BmBLOS gene appeared to be a heterozygote carrying the wild-type and mutation in most individuals, and the genotype of the BmBLOS gene was also different in all individuals. These results suggest that although the possibility of silkworm molecular breeding using the CRISPR/Cas9 system would be very high, continued research on breeding and screening methods will be necessary to improve gene editing efficiency and to obtain homozygotes.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.2
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• pp.318-331
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• 2019

In this study, comparative analysis is performed on the long-term persisted warm eddies that were generated in 2003 (WE03) and in 2014 (WE14) over the East Sea using the HYCOM reanalysis data. The overshooting of the East Korea Warm Current (EKWC) was appeared during the formation period of those warm eddies. The warm eddies were produced in the shallow Korea Plateau region through the interaction of the EKWC and the sub-polar front. In the interior of the both warm eddies, a homogeneous water mass of about $13^{\circ}C$ and 34.1 psu were generated over the upper 150 m depth by the winter mixing. In 2004, the next year of the generation of the WE03, the amount of the inflow through the western channel of the Korea Strait was larger, while the inflow was lesser than its climatology during 2015 corresponding to the development period of the WE14. The above results suggest that the heat and salt are supplied in the warm eddies through the Tsushima Warm Current (TWC), however the amount of the inflow through the Korea Strait has negligible impact on the long-term persistency of the warm eddies. Both of the warm eddies were maintained more than 18 months near Ulleung island, while they have no common feature on the pathways. In the vicinity of the Ulleung basin, large and small eddies are continuously created due to the meandering of the EKWC. The long-term persisted warm eddies in the Ulleung Island seem to be the results of the interaction between the pre-existed eddies located south of the sub-polar front and fresh eddies induced by the meanderings of the EKWC. The conclusion is also in line with the fact that the long-term persisted warm eddies were not always created when the overshooting of the EKWC was appeared.