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Comparative Analysis of Detection Methods for Food-borne Pathogens in Fresh-cut Agricultural Materials (신선 농산물내 식중독균 검출 방법의 비교 분석)

  • Jang, Hye-Jeong;Kim, Hye-Jeong;Park, Ji-in;Yu, Sun-Nyoung;Park, Bo-Bae;Ha, Gang-Ja;Ahn, Soon-Cheol;Kim, Dong-Seob
    • Journal of Life Science
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    • v.31 no.1
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    • pp.10-16
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    • 2021
  • The consumption of fresh-cut agricultural materials is increasing due to increased public interest in health and the increase of single-person households. Most fresh-cut agricultural materials can be eaten without heating, thus easily exposing the consumer to food-borne pathogens. As a result, food-borne diseases are increasing worldwide. In the analysis of food-borne pathogens, it is important to detect the strains, but this is time consuming and laborious. Alternative detection methods that have been introduced, include polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), which is performed without prior culturing. Samples of fresh-cut agricultural materials, such as vegetables, were analyzed by the culture-based method. In 129 samples, non-pathogenic Escherichia coli (3.9%), Bacillus cereus (31.8%), Clostridium perfringens (5.4%), Yersinia enterocolitica (0.8%), and enterohemorrhagic E. coli (0.8%) were detected. Eight samples contaminated with bacteria were randomly selected, further analyzed by PCR-DGGE, and compared with the culture-based method. Two cases detected non-pathogenic E. coli by PCR-DGGE only, despite a lack of detection by the culture method. It was supposed there was possibility of sample loss during its 10-fold dilution for appropriate cultivation. In the detection of high-risk food-borne pathogens, it was found that the detection limit was lower in PCR-DGGE than in the culture-based method (10 CFU/g). This suggests that PCR-DGGE can be alternatively used to detect strains. On the other hand, low-risk food-borne pathogens seem to have higher detection limits in PCR-DGGE. Consequentially, this study contributes to the improvement of food-borne pathogen detection and the prevention of its related-diseases in fresh-cut agricultural materials.

Analysis of Behavior of Seoullo 7017 Visitors - With a Focus on Text Mining and Social Network Analysis - (서울로 7017 방문자들의 이용행태 분석 -텍스트 마이닝과 소셜 네트워크 분석을 중심으로-)

  • Woo, Kyung-Sook;Suh, Joo-Hwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.6
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    • pp.16-24
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    • 2020
  • The purpose of this study is to analyze the usage behavior of Seoullo 7017, the first public garden in Korea, to understand the usage status by analyzing blogs, and to present usage behavior and improvement plans for Seoullo 7017. From June 2017 to May 2020, after Seoullo 7017 was open to citizens, character data containing 'Seoullo 7017' in the title and contents of NAVER and·DAUM blogs were converted to text mining and socialization, a Big Data technique. The analysis was conducted using social network analysis. The summary of the research results is as follows. First of all, the ratio of men and women searching for Seoullo 7017 online is similar, and the regions that searched most are in the order of Seoul and Gyeonggi, and those in their 40s and 50s were the most interested. In other words, it can be seen that there is a lack of interest in regions other than Seoul and Gyeonggi and among those in their 10s, 20s, and 30s. The main behaviors of Seoullo 7017 are' night view' and 'walking', and the factors that affect culture and art are elements related to culture and art. If various programs and festivals are opened and actively promoted, the main behavior will be more varied. On the other hand, the main behavior that the users of Seoullo 7017 want is 'sit', which is a static behavior, but the physical conditions are not sufficient for the behavior to occur. Therefore, facilities that can cause sitting behavior, such as shades and benches must be improved to meet the needs of visitors. The peculiarity of the change in the behavior of Seoullo 7017 is that it is recognized as a good place to travel alone and a good place to walk alone as a public multi-use facility and group activities are restricted due to COVID-19. Accordingly, in a situation like the COVD-19 pandemic, more diverse behaviors can be derived in facilities where people can take a walk, etc., and the increase of various attractions and the satisfaction of users can be increased. Seoullo 7017, as Korea's first public pedestrian area, was created for urban regeneration and the efficient use of urban resources in areas beyond the meaning of public spaces and is a place with various values such as history, nature, welfare, culture, and tourism. However, as a result of the use behavior analysis, various behaviors did not occur in Seoullo 7017 as expected, and elements that hinder those major behaviors were derived. Based on these research results, it is necessary to understand the usage behavior of Seoullo 7017 and to establish a plan for spatial system and facility improvement, so that Seoullo 7017 can be an important place for urban residents and a driving force to revitalize the city.

Kobong(高峯)'s Philophy and the theory of Self-cultivation(修養) (고봉(高峯)의 성리학(性理學)과 수양론(修養論))

  • Kang, Heui Bok
    • The Journal of Korean Philosophical History
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    • no.31
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    • pp.33-52
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    • 2011
  • This study intends to understand Kobong's thought, especially the problem of Self-cultivation. Kobong, along with Toegye(退溪), is a major figure to understand Confucian ideas of Chosun in the 16th century. There has been a lot of research centered on Kobong's Four-beginnings(四端) and Seven-emotions(七情), but not much on the Self-cultivation of Kobong. Confucianism is basically to seek after actualization of Perfect Virtue(仁) and the way to be a sage, through the pursuit of self-discipline(修己 明明德) and social practice(安人 新民). The problems of Confucianism might be summarized as follows: interest and appreciation for the source of existence(知天/事天); harmony in relationships and practices(愛人/愛物); both of the above together. Therefore, Self-cultivation is to change the self, the subject of one's life, through the relationship between man and heaven. Kobong and Toegye had debated for about eight years(1559-1566) over the problem of human nature, especially emotion(情), and virtue and vice(善惡) fundamental position of Toegye is that the difference between Four-beginnings(四端) and Seven-emotions(七情) can be understood as emotion with qualitative distinction. By contrast, Kobong sees the relationship between Four-beginnings(四端) and Seven-emotions(七情) as that of total and partial. Discussion on the Four-beginnings(四端) and Seven-emotions(七情) is not restricted within the problem of logical analysis of concepts or theoretical validity, but come to a conclusion with the problem of Self-cultivation(修養). In this sense, Kobong tried to follow Neo-Confucian theory of human nature and self-cultivation, on the assumption of Confucian self-discipline and social practice.

Characteristics of Playscript and Gramophone Record Reviewed through Theatrical Activities of Packaging Troupe Around the 1950s (1950년대 전후 포장극단의 연희활동으로 본 대본의 특성과 유성기음반)

  • You, Su-young
    • (The) Research of the performance art and culture
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    • no.35
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    • pp.229-247
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    • 2017
  • This study was conducted through the typological analysis of theatrical activities and playscript of Packaging Troupe, which was a wandering theater troupe. It seems the activities of the packaging troupe were very active about in the 1950s. They approached to the public with various repertoires and gained popularity during the process. The playscript used in their plays can be divided into several types such as Yi dynasty drama, historical drama and modern drama and their titles are almost same as or similar to those used in Changgeuk troupe (classical opera), Female Gukgeuk troupe (Female classical opera), or Female Nongak troupe (Female farm musical band). Also, as themes, subject matters, and characters were partially same, the characteristics of previous theatrical activities could be reviewed through the playscript of packaging troupe. Also, the characteristics of the playscript of packaging troupe can be found in the list of gramophone record. The changes in popular culture can be examined in the flow of plays with various forms such as theater, film, and gramophone through the comparison between the characteristics of playscript types of packaging troupe around in the 1950s and the list of gramophone record. A typological analysis of playscript of packaging troupe confirmed the activities of packaging troupe lasted around in the 1950s. Also it can be inferred from Hyeopryulsa, Changgeuk troupe, Female Gukgeuk troupe, or Female Nongak troupe, which used traditional subject matters as repertoire of performance. Those were possible because repertoires were composed and contents changed according to the needs of the public. The changes can be also confirmed through the list inserted in the gramophone record. The association can be inferred through the same title as that of the playscript of packaging troupe and similarity of performance curtains and subject matters. As such, the interest and flow of popular culture can be examined through the types of playscript of theatrical activities of packaging troupe.

On the Problem of Virtue in Confucian and Neoconfucian Philosophy (유학 및 신유학 철학에서의 덕의 문제)

  • Gabriel, Werner
    • (The)Study of the Eastern Classic
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    • no.50
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    • pp.89-120
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    • 2013
  • The concept of virtue seems to be one of the rare cases where the European and the Chinese traditions coincide. The meaning of the Latin word virtus and of Greek $aret{\acute{e}}$ seems to be similar to the Chinese $d{\acute{e}}$德. Most striking in virtue is that it is a capacity for self-realisation through action which is unique to man. On the other hand, there is something physical about it. It is the strength to do something. This strength overcomes the resistance of what is naturally given, it transforms the world, turns the natural world into a human one. In the Chinese tradition, $d{\acute{e}}$ 德, i.e. virtue, is therefore always connected with $da{\grave{o}}$ 道, the totality of natural forces. In the Chinese tradition, as opposed to the European one, virtue is itself considered to be a natural force that is present in man. This force sustains man's connectedness, unity and harmony with the surrounding world. Things exist through the unity of principle理 and ether氣. But the knowledge of this unity is due to principle. Moral and legal norms are shifted totally to the sphere of principle. Therefore their have found the final dissolution from a heroic models. Above all the classical Confucians, but also the other schools, would reply to this that there is nothing more precise than a concrete successful action. Its result fits the world perfectly. The difference is due to the differing interest of ethical thought. In the case of the Confucians the path is more direct. The actor establishes a precise pattern for other actions. Education therefore lies in detailed knowledge about forms of behaviour, not so much in conceptual differentiation. It is quite possible that generalisation may be a methodical prerequisite for success in this endeavour. That problem, too, is discussed. But the success of conceptualisation lies in the successful performance of individual actions, not in shaping actions in accordance with normative concepts.

Evaluation of Sprouted Barley as a Nutritive Feed Additive for Protaetia brevitarsis and Its Antibacterial Action against Serratia marcescens (흰점박이꽃무지 사료첨가제로서 새싹보리의 곤충병원성 세균에 대한 항균 효과에 관한 연구)

  • Song, Myung Ha;Kim, Nang-Hee;Park, Kwan-Ho;Kim, Eunsun;Kim, Yongsoon
    • Journal of Life Science
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    • v.31 no.5
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    • pp.475-480
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    • 2021
  • Interest in edible insects such as Protaetia brevitarsis has increased rapidly, and several insect producers use these insects in industrialized mass production. However, mass rearing of insects can cause insect diseases. Sprouted barley is a valuable source of nutrients and has antioxidant, antimicrobial, anti-inflammatory, and anti-cancer effects. This study was conducted to investigate the effect of sprouted barley as a feed additive for producing healthy P. brevitarsis larvae. P. brevitarsis larvae were fed feeds with or without sprouted barley, and their body weight and larval period wewe checked weekly. To confirm the antibacterial effects of sprouted barley, in vitro bioassays were performed by counting Serratia marcescens colonies, and in vivo bioassays were performed by determining the survival rate and body weights of the S. marcescens-infected larvae. Larvae fed different feeds were analyzed for their nutrient compositions (i.e., such as proximate composition, minerals, amino acids, and heavy metals). Larvae fed 5% and 10% sprouted barley had maximum weight increases of 19.2% and 23.1%, respectively. Both treatment groups had significantly shorter larval periods than those of the control group. Sprouted barley markedly inhibited the growth of entomopathogenic S. marcescens. Furthermore, larvae fed sprouted barley exhibited higher Cu, Zn, and K levels. Seventeen amino acids were present in larvae fed sprouted barley, of which, tyrosine and glutamic acid were predominant. No heavy metals were detected in any of the investigated groups. Therefore, sprouted barley may be a suitable feed additive for producing high-quality P. brevitarsis larvae.

International Research Trends Related to Inquiry in Science Education: Perception and Perspective on Inquiry, Support and Strategy for Inquiry, and Teacher Professional Development for Inquiry (과학교육에서 탐구 관련 국외 연구 동향 -탐구의 인식과 관점, 전략과 지원, 교사 전문성의 관점에서-)

  • Yu, Eun-Jeong;Byun, Taejin;Baek, Jongho;Shim, Hyeon-Pyo;Ryu, Kumbok;Lee, Dongwon
    • Journal of The Korean Association For Science Education
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    • v.41 no.1
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    • pp.33-46
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    • 2021
  • Inquiry occupies an important place in science education, and research related to inquiry is widely conducted. However, due to the inclusiveness of the concept of "exploration," each researcher perceives its meaning differently, and approaches may vary. In addition, criticisms have been raised that the results of classes using inquiry in science education do not guarantee meaningful changes to students. Therefore, this study attempts to identify the trend of SSCI-level research papers dealing with inquiry in science education over the past three years to confirm the current status and effectiveness of the inquiry. Researches used in the analysis are International Journal of Science Education, Journal of Research in Science Teaching, Research in Science Education, and Science Education, and limited to those that directly suggest "inquiry (enquiry)" as a keyword. Based on extracted 75 papers, the classification process was conducted, and an analysis frame was derived inductively by reflecting the subject and characteristics. Specific cases for each category were presented by dividing into three aspects: perception and perspective on inquiry, support and strategy for inquiry, and teacher professional development for inquiry. The results of examining the implications for scientific inquiry are as follows: First, rather than defining inquiry as an implicit proposition or presenting it as a step-by-step procedure, it was induced to grasp the meaning of inquiry more comprehensively and holistically. Second, as to whether the inquiry-based instruction is effective in all aspects of the cognitive, functional, and affective domains of science, the limitations are clearly presented, and the context-dependent and subject-specific properties and limitations of inquiry are emphasized. Third, uncertainty in science inquiry-based instruction can help learners to begin their inquiry and develop interest, but in the process of recognizing data and restructuring knowledge, explicit and specific guidance and scaffolding should be provided at an appropriate timing.

Performance of a Molten Carbonate Fuel Cell With Direct Internal Reforming of Methanol (메탄올 내부개질형 용융탄산염 연료전지의 성능)

  • Ha, Myeong Ju;Yoon, Sung Pil;Han, Jonghee;Lim, Tae-Hoon;Kim, Woo Sik;Nam, Suk Woo
    • Clean Technology
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    • v.26 no.4
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    • pp.329-335
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    • 2020
  • Methanol synthesized from renewable hydrogen and captured CO2 has recently attracted great interest as a sustainable energy carrier for large-scale renewable energy storage. In this study, molten carbonate fuel cell's performance was investigated with the direct conversion of methanol into syngas inside the anode chamber of the cell. The internal reforming of methanol may significantly improve system efficiency since the heat generated from the electrochemical reaction can be used directly for the endothermic reforming reaction. The porous Ni-10 wt%Cr anode was sufficient for the methanol steam reforming reaction under the fuel cell operating condition. The direct supply of methanol into the anode chamber resulted in somewhat lower cell performance, especially at high current density. Recycling of the product gas into the anode gas inlet significantly improved the cell performance. The analysis based on material balance revealed that, with increasing current density and gas recycling ratio, the methanol steam reforming reaction rate likewise increased. A methanol conversion more significant than 90% was achieved with gas recycling. The results showed the feasibility of electricity and syngas co-production using the molten carbonate fuel cell. Further research is needed to optimize the fuel cell operating conditions for simultaneous production of electricity and syngas, considering both material and energy balances in the fuel cell.

Performance of Investment Strategy using Investor-specific Transaction Information and Machine Learning (투자자별 거래정보와 머신러닝을 활용한 투자전략의 성과)

  • Kim, Kyung Mock;Kim, Sun Woong;Choi, Heung Sik
    • Journal of Intelligence and Information Systems
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    • v.27 no.1
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    • pp.65-82
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    • 2021
  • Stock market investors are generally split into foreign investors, institutional investors, and individual investors. Compared to individual investor groups, professional investor groups such as foreign investors have an advantage in information and financial power and, as a result, foreign investors are known to show good investment performance among market participants. The purpose of this study is to propose an investment strategy that combines investor-specific transaction information and machine learning, and to analyze the portfolio investment performance of the proposed model using actual stock price and investor-specific transaction data. The Korea Exchange offers daily information on the volume of purchase and sale of each investor to securities firms. We developed a data collection program in C# programming language using an API provided by Daishin Securities Cybosplus, and collected 151 out of 200 KOSPI stocks with daily opening price, closing price and investor-specific net purchase data from January 2, 2007 to July 31, 2017. The self-organizing map model is an artificial neural network that performs clustering by unsupervised learning and has been introduced by Teuvo Kohonen since 1984. We implement competition among intra-surface artificial neurons, and all connections are non-recursive artificial neural networks that go from bottom to top. It can also be expanded to multiple layers, although many fault layers are commonly used. Linear functions are used by active functions of artificial nerve cells, and learning rules use Instar rules as well as general competitive learning. The core of the backpropagation model is the model that performs classification by supervised learning as an artificial neural network. We grouped and transformed investor-specific transaction volume data to learn backpropagation models through the self-organizing map model of artificial neural networks. As a result of the estimation of verification data through training, the portfolios were rebalanced monthly. For performance analysis, a passive portfolio was designated and the KOSPI 200 and KOSPI index returns for proxies on market returns were also obtained. Performance analysis was conducted using the equally-weighted portfolio return, compound interest rate, annual return, Maximum Draw Down, standard deviation, and Sharpe Ratio. Buy and hold returns of the top 10 market capitalization stocks are designated as a benchmark. Buy and hold strategy is the best strategy under the efficient market hypothesis. The prediction rate of learning data using backpropagation model was significantly high at 96.61%, while the prediction rate of verification data was also relatively high in the results of the 57.1% verification data. The performance evaluation of self-organizing map grouping can be determined as a result of a backpropagation model. This is because if the grouping results of the self-organizing map model had been poor, the learning results of the backpropagation model would have been poor. In this way, the performance assessment of machine learning is judged to be better learned than previous studies. Our portfolio doubled the return on the benchmark and performed better than the market returns on the KOSPI and KOSPI 200 indexes. In contrast to the benchmark, the MDD and standard deviation for portfolio risk indicators also showed better results. The Sharpe Ratio performed higher than benchmarks and stock market indexes. Through this, we presented the direction of portfolio composition program using machine learning and investor-specific transaction information and showed that it can be used to develop programs for real stock investment. The return is the result of monthly portfolio composition and asset rebalancing to the same proportion. Better outcomes are predicted when forming a monthly portfolio if the system is enforced by rebalancing the suggested stocks continuously without selling and re-buying it. Therefore, real transactions appear to be relevant.

Analysis of Literatures Related to Crop Growth and Yield of Onion and Garlic Using Text-mining Approaches for Develop Productivity Prediction Models (양파·마늘 생산성 예측 모델 개발을 위한 텍스트마이닝 기법 활용 생육 및 수량 관련 문헌 분석)

  • Kim, Jin-Hee;Kim, Dae-Jun;Seo, Bo-Hun;Kim, Kwang Soo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.374-390
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    • 2021
  • Growth and yield of field vegetable crops would be affected by climate conditions, which cause a relatively large fluctuation in crop production and consumer price over years. The yield prediction system for these crops would support decision-making on policies to manage supply and demands. The objectives of this study were to compile literatures related to onion and garlic and to perform data-mining analysis, which would shed lights on the development of crop models for these major field vegetable crops in Korea. The literatures on crop growth and yield were collected from the databases operated by Research Information Sharing Service, National Science & Technology Information Service and SCOPUS. The keywords were chosen to retrieve research outcomes related to crop growth and yield of onion and garlic. These literatures were analyzed using text mining approaches including word cloud and semantic networks. It was found that the number of publications was considerably less for the field vegetable crops compared with rice. Still, specific patterns between previous research outcomes were identified using the text mining methods. For example, climate change and remote sensing were major topics of interest for growth and yield of onion and garlic. The impact of temperature and irrigation on crop growth was also assessed in the previous studies. It was also found that yield of onion and garlic would be affected by both environment and crop management conditions including sowing time, variety, seed treatment method, irrigation interval, fertilization amount and fertilizer composition. For meteorological conditions, temperature, precipitation, solar radiation and humidity were found to be the major factors in the literatures. These indicate that crop models need to take into account both environmental and crop management practices for reliable prediction of crop yield.