• Title/Summary/Keyword: cases study

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Application of Amplitude Demodulation to Acquire High-sampling Data of Total Flux Leakage for Tendon Nondestructive Estimation (덴던 비파괴평가를 위한 Total Flux Leakage에서 높은 측정빈도의 데이터를 획득하기 위한 진폭복조의 응용)

  • Joo-Hyung Lee;Imjong Kwahk;Changbin Joh;Ji-Young Choi;Kwang-Yeun Park
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.2
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    • pp.17-24
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    • 2023
  • A post-processing technique for the measurement signal of a solenoid-type sensor is introduced. The solenoid-type sensor nondestructively evaluates an external tendon of prestressed concrete using the total flux leakage (TFL) method. The TFL solenoid sensor consists of primary and secondary coils. AC electricity, with the shape of a sinusoidal function, is input in the primary coil. The signal proportional to the differential of the input is induced in the secondary coil. Because the amplitude of the induced signal is proportional to the cross-sectional area of the tendon, sectional loss of the tendon caused by ruptures or corrosion can be identified by the induced signal. Therefore, it is important to extract amplitude information from the measurement signal of the TFL sensor. Previously, the amplitude was extracted using local maxima, which is the simplest way to obtain amplitude information. However, because the sampling rate is dramatically decreased by amplitude extraction using the local maxima, the previous method places many restrictions on the direction of TFL sensor development, such as applying additional signal processing and/or artificial intelligence. Meanwhile, the proposed method uses amplitude demodulation to obtain the signal amplitude from the TFL sensor, and the sampling rate of the amplitude information is same to the raw TFL sensor data. The proposed method using amplitude demodulation provides ample freedom for development by eliminating restrictions on the first coil input frequency of the TFL sensor and the speed of applying the sensor to external tension. It also maintains a high measurement sampling rate, providing advantages for utilizing additional signal processing or artificial intelligence. The proposed method was validated through experiments, and the advantages were verified through comparison with the previous method. For example, in this study the amplitudes extracted by amplitude demodulation provided a sampling rate 100 times greater than those of the previous method. There may be differences depending on the given situation and specific equipment settings; however, in most cases, extracting amplitude information using amplitude demodulation yields more satisfactory results than previous methods.

Determining the Authenticity of Labeled Traceability Information by DNA Identity Test for Hanwoo Meats Distributed in Seoul, Korea (DNA 동일성 검사를 통한 서울지역 유통 한우육의 표시 이력정보 진위 판별)

  • Yeon-jae Bak;Mi-ae Park;Su-min Lee;Hyung-suk Park
    • Journal of Food Hygiene and Safety
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    • v.38 no.1
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    • pp.12-18
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    • 2023
  • Beef traceability systems help prevent the distribution of Hanwoo (Korean native cattle) meat as imported beef. In particular, assigning a traceability number to each cattle can provide all information regarding the purchased Hanwoo meat to the consumers. In the present study, a DNA identity test was conducted on 344 samples of Hanwoo meat from large livestock product stores in Seoul between 2021 and 2022 to determine the authenticity of important label information, such as the traceability number. Traceability number mismatch was confirmed in 45 cases (13.1%). The mismatch rate decreased to 11.3% in 2022 from 14.7% in 2021, and the mismatch rate was higher in the northern region (16.9%) than in the southern region (10.2%). In addition, of the six brands, B and D showed satisfactory traceability system management, whereas E and A showed poor traceability system management, with significant differences (P<0.001). The actual traceability number confirmation rate was only 53.9% among the mismatch samples. However, examination of the authenticity of label information of the samples within the identified range revealed false marking in the order of the traceability number (13.1%), sex (2.9%), slaughterhouse name (2.2%), and grade (1.6%); no false marking of breed (Hanwoo) was noted. To prevent the distribution of erroneously marked livestock products, the authenticity of label information must be determined promptly. Therefore, a legal basis must be established mandating the filling of a daily work sheet, including the traceability number of beef, in partial meat subdivisions. Our findings can be used as reference data to guide the management direction of traceability systems for ensuring transparency in the distribution of livestock products.

Etiology and Risk Factors of Community-Acquired Pneumonia in Hospitalized Children During the COVID-19 Pandemic in South Korea (국내 코로나19 판데믹 기간 발생한 입원을 요하는 소아청소년 지역사회폐렴의 원인과 위험 인자)

  • Hae Min Kang;Seung Ha Song;Bin Ahn;Ji Young Park;Hyunmi Kang;Byung Ok Kwak;Dong Hyun Kim;Joon Kee Lee;Soo-Han Choi ;Jae Hong Choi;Eun Hwa Choi;Ki Wook Yun
    • Pediatric Infection and Vaccine
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    • v.30 no.1
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    • pp.20-32
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    • 2023
  • Purpose: This study aimed to identify the etiology and risk factors of community-acquired pneumonia (CAP) requiring hospitalization in Korean children during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Clinical information of children admitted with CAP to Seoul National University Children's Hospital (SNUCH) between January 1, 2021, and February 28, 2022, was retrospectively collected and analyzed. In addition, the etiologic diagnosis and demographic data of children with CAP who were discharged at the other seven hospitals between January and February 2022 were collected. Pneumonia was diagnosed using strict criteria comprising clinical symptoms, physical examination findings, and chest radiographic findings. Results: Among 91 children hospitalized with CAP at SNUCH during the 14-month period, 68.4% were aged <5 years and 79.1% had underlying diseases. Among the 95 CAP cases, respiratory assistance was required in 70.5%, and the use of a ventilator was required in 20.0%. A total of five patients expired, all of whom were either immunocompromised or had underlying neurological diseases. Neurological diseases and immunosuppression were significantly correlated with respiratory assistance (P=0.003) and death (P=0.014). A total of 55% of the detected respiratory pathogens were viruses, the most common of which was rhinovirus at 35.9%. Among the 169 children hospitalized for CAP at the eight institutions, ≥1 respiratory virus was detected in 92.3%, among which respiratory syncytial virus (79.8%) was the most prevalent. Conclusions: Even during the COVID-19 pandemic, Korean children were hospitalized with CAP caused by seasonal respiratory viral pathogens. Although atypical and pyogenic bacteria were not detected, continuous clinical monitoring and further prospective studies should be conducted.

The Critic on Mohism in the History of Korean Thoughts Centered on the Theory of Rejecting Heterodoxy (한국사상사에서의 묵가(墨家) 비판 - 벽리단론(闢異端論)의 전개 양상을 중심으로 -)

  • Yun, Muhak
    • The Journal of Korean Philosophical History
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    • no.29
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    • pp.89-123
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    • 2010
  • As above, as theoretical basis of critiques against School of Mohism, the researcher summarized the positions of the elder Confucian scholars including Meng Zi. In the body of text, taking it as promises, the researcher examined the critiques against Mo Tzu and School of Mohism as well focusing on the aspects and development of the theory of rejecting heterodoxy which had been introduced and strongly argued from the end of Goryeo kingdom to the late Joseon period. The summary of the body of this text is as follows: In the old literatures prior to Goryeo Kingdom, the researcher couldn't find any cases that either the School of Mohism or Mo Tzu including the Hundred Schools of Thought had been rejected explicitly. Having reached the end of Goryeo and the beginning of Joseon period, Meng Zi's viewpoints on the theory of rejecting heterodoxy had begun to emerge and come into play with the progress of accepting Neo-Confucianism, and, these critiques against Yang Zhu and Mo Tzu being given, the scholar-literati circle had started rejecting Buddhism and Lao Tzu. Basically the contents of the critiques against the School of Mohism in the early period of Joseon were in succession to Meng Zi's theory of rejecting heterodoxy and the views and thoughts of the elder Confucian scholars including Han Yu rather than any specific critiques against Mo Tzu' ideology itself. Until entering the middle of Joseon period, the critiques against the School of Mohism had been used as a tool to promote Confucianism in an affirmative manner, while arguing strongly against the viewpoint of Han Yu in the first place. Particularly, not only the original text of the Mo Tzu's writings were directly quoted, although it was partial, but also the contents of the critiques against the School of Mohism had been developed and stretched to the extent of their entire ideological system. Having approached to the late period of Joseon, the critiques against the School of Mohism had begun to be linked to those critiques against the study of state examination or of sentence patterns including Catholic Church, furthermore the critics raised their harsh tones against the irregularities of the society at large like the issue of corruptions of the government officials of those days instead, although they still had firmly stood on the ground of the theory of rejecting heterodoxy. Those scholars that belonged to the School of Practical Learning, in particular, said in justification of the School of Mohism arguing that the major ideologies of Mo Zi had usefulness in the real world, also they even evaluated that Meng Zi ' critiques against the School of Mohism were immoderate. To sum up, characteristics of scholars in the Joseon period to understand and critique the School of Mohism are that ideologies of Mo Tzu were mostly used as a tool for the sake of critiques against heresies in other sectors of society based mainly on Meng Zi's theory of rejecting heterodoxy, rather than opposing views against the ideologies or philosophies of the School of Mohism itself. Meanwhile, however, on the plus side, the critics praised Mo Tzu's individual efforts in order to put his ideology of peace into practice apart from the ideological system of the School of Mohism. Also, having reached the late period of Joseon, the researcher was able to have discovered the fact that the writings of Mo Tzu had been used as historical materials in order to ascertain historical truths of Confucian Scriptures, rather not having it regarded as an ideology text.

A Study on the Musical Characteristics of Fishing songs in North Korea (북한 어업노동요의 음악적 특징)

  • Kim, Jeong-Hee
    • (The) Research of the performance art and culture
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    • no.39
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    • pp.279-323
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    • 2019
  • The musical characteristics of Fishing songs in North Korean which recorded on Anthology of North Korean Folk Songs were examined in this paper. The results are as follows. Among Fishing songs in North Korea, there are "Rowing Song," the "Song for Hauling Nets," and the "Song for Picking Up Fish" in songs related to walleye pollack fishing and in songs related to croaker fishing, the "Song for Dropping Anchor" and the "Full-Load-of-Fish Song" in songs related to croaker fishing, the "Song for Weighing Anchor," the "Song for Shaking Fish," the "Full-Load-of-Fish Rowing Song," and the "Song for Hanging Walleye Pollack" in songs related to walleye pollack fishing. There are the "Song for Setting a sail" and the "Song for catching shells" in Fishing songs in North Korea, too. In the rhythmic elements of Fishing songs in North Korea, the tempo of the "Songs for Setting a sail" is moderato, and that of the "Songs for Picking Up Fish" of songs related to anchovy or herring fishing is quite slow. "Rowing Songs"(croaker fishing) have various tempos but faster than moderato, and usually get faster and faster as time goes by. Most songs have 4/♩. time and there are some of 2, 3 or 5 time. Some songs use irregular time or 6 time overlapping 2 beats. The mode Menari is the most common tonal system used in fishing songs of North Korea. And the mode Susimga, the mode Changbutaryeong, the mode Nanbongga, and the mode Odolttogi are also used in the tonal system of Fishing songs in North Korea. There are shoutting intonations that have indefinite pitch, too. Modulation or interaction by the mode Changbutaryeong appeared in songs of the mode Menari. There is a tendency to favor a certain tonal system by category. Responsorial form is mostly used, but in the most cases, they were sung in solo. In responsorial songs, several calling songs overlap with the responding songs. Durchkomponiert form is sung by antiphon or in solo, but the case sung in solo originally seems to have been sung by antiphon or unison, if we consider the procedure of the work. The "Song for Picking Up Fish" of Seonbong-gun of North Hamgyeong Province and Yangyang-gun of Gangwon Province, the "Full-Load-of-Fish Song-Bongjuktaryeong" of Jeungsan-gun of South Pyeongan Province and "Full-Load-of-Fish Song-Baechigisory" of Taean-gun of South Chungcheong Province, "Rowing Song" of Nampo City and Ganghwa-gun of Gyeonggi Province are resembled. In neighboring areas, even if the songs of different categorys, sometimes share a same melody. In a certain category, sometimes a same melody is shared to a considerable distance. It was first identified that in anchovy or herring fishing or dybowskii' sand eel fishing, the "Song for Picking Up Fish" is widely shared in the East Sea Coast area.

Text Mining of Successful Casebook of Agricultural Settlement in Graduates of Korea National College of Agriculture and Fisheries - Frequency Analysis and Word Cloud of Key Words - (한국농수산대학 졸업생 영농정착 성공 사례집의 Text Mining - 주요단어의 빈도 분석 및 word cloud -)

  • Joo, J.S.;Kim, J.S.;Park, S.Y.;Song, C.Y.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.20 no.2
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    • pp.57-72
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    • 2018
  • In order to extract meaningful information from the excellent farming settlement cases of young farmers published by KNCAF, we studied the key words with text mining and created a word cloud for visualization. First, in the text mining results for the entire sample, the words 'CEO', 'corporate executive', 'think', 'self', 'start', 'mind', and 'effort' are the words with high frequency among the top 50 core words. Their ability to think, judge and push ahead with themselves is a result of showing that they have ability of to be managers or managers. And it is a expression of how they manages to achieve their dream without giving up their dream. The high frequency of words such as "father" and "parent" is due to the high ratio of parents' cooperation and succession. Also 'KNCAF', 'university', 'graduation' and 'study' are the results of their high educational awareness, and 'organic farming' and 'eco-friendly' are the result of the interest in eco-friendly agriculture. In addition, words related to the 6th industry such as 'sales' and 'experience' represent their efforts to revitalize farming and fishing villages. Meanwhile, 'internet', 'blog', 'online', 'SNS', 'ICT', 'composite' and 'smart' were not included in the top 50. However, the fact that these words were extracted without omission shows that young farmers are increasingly interested in the scientificization and high-tech of agriculture and fisheries Next, as a result of grouping the top 50 key words by crop, the words 'facilities' in livestock, vegetables and aquatic crops, the words 'equipment' and 'machine' in food crops were extracted as main words. 'Eco-friendly' and 'organic' appeared in vegetable crops and food crops, and 'organic' appeared in fruit crops. The 'worm' of eco-friendly farming method appeared in the food crops, and the 'certification', which means excellent agricultural and marine products, appeared only in the fishery crops. 'Production', which is related to '6th industry', appeared in all crops, 'processing' and 'distribution' appeared in the fruit crops, and 'experience' appeared in the vegetable crops, food crops and fruit crops. To visualize the extracted words by text mining, we created a word cloud with the entire samples and each crop sample. As a result, we were able to judge the meaning of excellent practices, which are unstructured text, by character size.

Verification of International Trends and Applicability in the Republic of Korea for a Greenhouse Gas Inventory in the Grassland Biomass Sector (초지 바이오매스 부문 온실가스 인벤토리 구축을 위한 국제 동향과 국내 적용 가능성 평가)

  • Sle-gee Lee;Jeong-Gwan Lee;Hyun-Jun Kim
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.43 no.4
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    • pp.257-267
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    • 2023
  • The grassland section of the greenhouse gas inventory has limitations due to a lack of review and verification of biomass compared to organic carbon in soil while grassland is considered one of the carbon storages in terrestrial ecosystems. Considering the situation at internal and external where the calculation of greenhouse gas inventory is being upgraded to a method with higher scientific accuracy, research on standards and methods for calculating carbon accumulation of grassland biomass is required. The purpose of this study was to identify international trends in the calculation method of the grassland biomass sector that meets the Tier 2 method and to conduct a review of variables applicable to the Republic of Korea. Identify the estimation methods and access levels for grassland biomass through the National Inventory Report in the United Nations Framework Convention on Climate Change and type the main implications derived from overseas cases. And, a field survey was conducted on 28 grasslands in the Republic of Korea to analyse the applicability of major issues. Four major international issues regarding grassland biomass were identified. 1) country-specific coefficients by land use; 2) calculations on woody plants; 3) loss and recovery due to wildfire; 4) amount of change by human activities. As a result of field surveys and analysis of activity data available domestically, it was found that there was a significant difference in the amount of carbon in biomass according to use type classification and climate zone-soil type classification. Therefore, in order to create an inventory of grassland biomass at the Tier 2 level, a policy and institutional system for making activity data should develop country-specific coefficients for climate zones and soil types.

A study on spatial onset characteristics of flash drought based on GLDAS evaporative stress in the Korean Peninsula (GLDAS 증발 스트레스 기반 한반도 돌발가뭄의 공간적 발생 특성 연구)

  • Kang, Minsun;Jeong, Jaehwan;Lee, Seulchan;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.56 no.10
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    • pp.631-639
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    • 2023
  • Flash drought (FD), characterized by the rapid onset and intensification, can significantly impact ecosystems and induce immediate water stress. A more comprehensive understanding of the causes and characteristics of FD events is required to enhance drought monitoring. Therefore, we investigated the FD events took place over the Korean peninsula using Global Land Data Assimilation System (GLDAS) data from 2012 to 2022. We first detected FD events using the stress-based method (Standardized Evaporative Stress Ratio, SESR), and analyzed the frequency and duration of FDs. The FD events were classified into three cases based on the variations in Actual Evapotranspiration (AET) and potential Evapotranspiration (PET), and spatially analyzed. Results revealed that there are regional disparities in frequency and duration of FDs, with a mean frequency of 6.4 and duration of 31 days. When classified into Case 1 (normal condition), Case 2 (AET-driven), and Case 3 (PET-driven), we found that Case 2 FDs emerged approximately 1.5 times more frequently than those driven by PET (Case 3) across the Korean peninsula. Case 2 FDs were found to be induced under water-limited conditions, and led both AET and PET to be decreased. Conversely, Case 3 FDs occurred under energy-limited conditions, with increase in both. Case 2 FDs predominantly affected the northwestern and central-southern agricultural regions, while Case 3 occurred in the eastern region, characterized by forested land cover. These findings offers insights into our understanding of FDs over the Korean peninsula, considering climate factors, land cover, and water availability.

Development of Weight Estimation Equations and Weight Tables for Larix kaempferi and Pinus rigida Stand (일본잎갈나무와 리기다소나무의 중량추정식 및 중량표 개발)

  • Jintaek Kang;Chiung Ko;Jeongmuk Park;Jongsu Yim;Sun-Jeong Lee;Myoungsoo Won
    • Journal of Korean Society of Forest Science
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    • v.112 no.4
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    • pp.472-489
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    • 2023
  • This study was conducted to derive the optimal estimation equations for deriving the green and dry weights of Larix kaempferi (Japanese larch) and Pinus rigida (Rigida pine), which are major coniferous tree species in South Korea. The equations were then used to develop weight tables. Table development began with the sampling of 150 L. kaempferi and 90 P. rigida trees distributed throughout the national scale, after which green weights were measured on-site. Samples from each stand were then collected, and their dry weights were measured in a laboratory. The equation used to calculate green and dry weights was divided into a one-variable formula that uses only the diameter at breast height (DBH) and a two-variable equation that employs DBH and height. The equations used to estimate the green and dry weights of logs were divided into one- and two-variable equations using DBH. Statistical data, such as the fitness index (FI), root mean square error, standard error of estimation, and residual diagram, were used to verify the suitability of the estimation equations. Applicability was examined by calculating weights using the derived optimal equations. The equation W = bD+cD2 was used in measurements involving only DBH, whereas the equation W = aDbHc was employed in cases involving both diameter and height at breast height. The FI of W = bD+cD2 was 0.91, while that of W = aDbHc was 0.95, both of which are high values. With these estimation formulas, weight tables for the green and dry weights of L. kaempferi and P. rigida were prepared and compared with weight tables created 20 years ago. The green and dry weight tables of both species were larger.

A Study on the Liability of Artificial Person(Natural Persons) with a Disregard of the Corporate Fiction in ESG (ESG측면에서의 법인격 부인과 법인관계인(자연인)의 책임에 관한 연구)

  • Kim, Dong-han;Kwon, Yong-man
    • Journal of Venture Innovation
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    • v.4 no.3
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    • pp.141-150
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    • 2021
  • Although management decisions centered on the board of directors and directors must be made in order to effectively promote ESG management, the company's management is not obligated to make decisions considering ESG factors. A Korean corporation(company) is an established organization for commercial or other profit, and the purpose of treating a legal organization as a corporation is to easily handle the legal relationship of a group (corporate's property) and individual property of a group member, but legal person such as rights to "harm public rights" or "defend fraud". Criminal liability for illegal acts of a corporation, but the liability of a corporation (natural person) for illegal acts of a corporation is recognized within a limited range, but the criminal liability of a corporation (natural person) is limited. As the social responsibility of a corporation is great, limiting the responsibility of a corporation-related person (natural person) to civil responsibility will halve its effectiveness if considering the impact on the corporation's national economy. Objective requirements such as the completeness of control, hybridization of property, infringement of creditors' rights, and small-capitalization, and the subjective intention of abusing the company system to avoid legal application to controlling shareholders should be denied. Despite the increasing influence on corporate society, such as large-scale projects and astronomical business profits, corporate officials (natural persons) are forced to be held liable for negligence and intentional liability within a limited range. In such cases, it is necessary to introduce criminal responsibility separately from civil responsibility to legal persons (natural persons) in consideration of the maturity of capitalism in Korean society and the economic status of the world. In Korea, the requirements for recognition of corporate denial are strict, but the United States says that it is sufficient to have control or fraud. Therefore, it is not about civil responsibility, but about criminal responsibility of a legal person (natural person), so if fraud is recognized, it can strengthen the corporate social responsibility.