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A Study on Reduction of Cavitation with Orifice on High Differential Pressure Control Butterfly Valve (오리피스를 이용한 고차압 제어 버터플라이 밸브의 캐비테이션 저감에 관한 연구)

  • Lee, Sang-Beom
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.1
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    • pp.131-139
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    • 2022
  • The exchange of goods over the sea is a situation in which the amount of trade between countries is gradually increasing. In order to maintain the optimal operating condition, the ship maintains stability and optimal operating conditions by inserting or withdrawing ballast water from the ballast tank according to the loading condition of cargo capacity is also increasing. Control valves play an important role in controlling fluid flow in these pipes. When the flow rate is controlled using a control valve, problems such as cavitation, flashing, and suffocating flow may occur due to high differential pressure, and in particular, damage to valves and pipes due to cavitation is a major problem. Therefore, in this study, the cavitation phenomenon is reduced by installing orifices at the front and rear ends of the high differential pressure control butterfly valve to reduce the sudden pressure drop at the limiting part of the butterfly valve step by step. The flow coefficient according to the shape of the orifice, the degree of cavitation occurrence, and the correlation were analyzed using a CFD(Cumputational Fluid Dynamics), and an optimal orifice design for reducing cavitation is derived.

Topic Modeling Analysis of Social Media Marketing using BERTopic and LDA

  • YANG, Woo-Ryeong;YANG, Hoe-Chang
    • The Journal of Industrial Distribution & Business
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    • v.13 no.9
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    • pp.37-50
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    • 2022
  • Purpose: The purpose of this study is to explore and compare research trends in Korea and overseas academic papers on social media marketing, and to present new academic perspectives for the future direction in Korea. Research design, data and methodology: We used English abstract of research paper (Korea's: 1,349, overseas': 5,036) for word frequency analysis, topic modeling, and trend analysis for each topic. Results: The results of word frequency and co-occurrence frequency analysis showed that Korea researches focused on the experiential values of users, and overseas researches focused on platforms and content. Next, 13 topics and 12 topics for Korea and overseas researches were derived from topic modeling. And, trend analysis showed that Korean studies were different from overseas in applying marketing methods to specific industries and they were interested in the short-term performance of social media marketing. Conclusions: We found that the long-term strategies of social media marketing and academic interest in the overall industry will necessary in the future researches. Also, data mining techniques will necessary to generate more general results by quantifying various phenomena in reality. Finally, we expected that continuous and various academic approaches for volatile social media is effective to derive practical implications.

Classification of Livestock Diseases Using GLCM and Artificial Neural Networks

  • Choi, Dong-Oun;Huan, Meng;Kang, Yun-Jeong
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.173-180
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    • 2022
  • In the naked eye observation, the health of livestock can be controlled by the range of activity, temperature, pulse, cough, snot, eye excrement, ears and feces. In order to confirm the health of livestock, this paper uses calf face image data to classify the health status by image shape, color and texture. A series of images that have been processed in advance and can judge the health status of calves were used in the study, including 177 images of normal calves and 130 images of abnormal calves. We used GLCM calculation and Convolutional Neural Networks to extract 6 texture attributes of GLCM from the dataset containing the health status of calves by detecting the image of calves and learning the composite image of Convolutional Neural Networks. In the research, the classification ability of GLCM-CNN shows a classification rate of 91.3%, and the subsequent research will be further applied to the texture attributes of GLCM. It is hoped that this study can help us master the health status of livestock that cannot be observed by the naked eye.

A Study on Leadership Trends from the Perspective of Domestic Researcher's Using BERTopic and LDA

  • Sung-Su, SHIN;Hoe-Chang, Yang
    • East Asian Journal of Business Economics (EAJBE)
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    • v.11 no.1
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    • pp.53-71
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    • 2023
  • Purpose - This study aims to find clues necessary for the direction of leadership development suitable for the current situation by exploring the direction in which leadership has been studied from the perspective of domestic researchers, along with the arrangement of leadership theories studied in various ways. Research design, data, and methodology - A total of 7,425 papers were obtained due to the search, and 5,810 papers with English abstracts were used for analysis. For analysis, word frequency analysis, word clouding, and co-occurrence were confirmed using Python 3.7. In addition, after classifying topics related to research trends through BERTopic and LDA, trends were identified through dynamic topic modeling and OLS regression analysis. Result - As a result of the BERTopic, 14 topics such as 'Leadership management and performance' and 'Sports leadership' were derived. As a result of conducting LDA on 1,976 outliers, five topics were derived. As a result of trend analysis on topics by year, it was confirmed that five topics, such as 'military police leadership' received relative attention. Conclusion - Through the results of this study, a study on the reinterpretation of past leadership studies, a study on LMX with an expanded perspective, and a study on integrated leadership sub-factors of modern leadership theory were proposed.

The Dynamics of Research Output by Indonesian Scientist, Period of 1945-2021

  • Prakoso Bhairawa, Putera;Ida, Widianingsih;Sinta, Ningrum;Suryanto, Suryanto;Yan, Rianto
    • Asian Journal of Innovation and Policy
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    • v.11 no.3
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    • pp.397-420
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    • 2022
  • This research was conducted by applying a bibliometric analysis to determine the dynamics of research topics from ten percent of research output (international publications) generated by Indonesian scientists from the period of 1945-2021. This study utilizes VOSviewers version 1.6.18 for analysis and visualization of bibliometric networks. The research results indicate that 50.24% of Indonesian international publications are published in the form of articles, with subjects such as: Agricultural and Biological Sciences, Medicine, and Earth and Planetary Sciences as the most dominating subject areas. Regarding the author, Tjia, MO from Bandung Institute of Technology was acknowledged as the top author in terms of the number of publications produced for two periods. The article entitled "Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: A systematic analysis for the Global Burden of Disease Study 2013" (Ng et al., 2014) became the most cited one.

Online Shopping Research Trend Analysis Using BERTopic and LDA

  • Yoon-Hwang, JU;Woo-Ryeong, YANG;Hoe-Chang, YANG
    • The Journal of Economics, Marketing and Management
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    • v.11 no.1
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    • pp.21-30
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    • 2023
  • Purpose: As one of the ongoing studies on the distribution industry, the purpose of this study is to identify the research trends on online shopping so far to propose not only the development of online shopping companies but also the possibility of coexistence between online and offline retailers and the development of the distribution industry. Research design, data and methodology: In this study, the English abstracts of 645 papers on online shopping registered in scienceON were obtained. For the analysis through BERTopic and LDA using Python 3.7 and identifying which topics were interesting to researchers. Results: As a result of word frequency analysis and co-occurrence analysis, it was found that studies related to online shopping were frequently conducted on factors such as products, services, and shopping malls. As a result of BERTopic, five topics such as 'service quality' and 'sales strategy' were derived, and as a result of LDA, three topics including 'purchase experience' were derived. It was confirmed that 'Customer Recommendation' and 'Fashion Mall' showed relatively high interest, and 'Sales Strategy' showed relatively low interest. Conclusions: It was suggested that more diverse studies related to the online shopping mall platform, sales content, and usage influencing factors are needed to develop the online shopping industry.

Developing a Classification of Vulnerabilities for Smart Factory in SMEs: Focused on Industrial Control Systems (중소기업용 스마트팩토리 보안 취약점 분류체계 개발: 산업제어시스템 중심으로)

  • Jeong, Jae-Hoon;Kim, Tae-Sung
    • Journal of Information Technology Services
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    • v.21 no.5
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    • pp.65-79
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    • 2022
  • The smart factory has spread to small and mid-size enterprises (SMEs) under the leadership of the government. Smart factory consists of a work area, an operation management area, and an industrial control system (ICS) area. However, each site is combined with the IT system for reasons such as the convenience of work. As a result, various breaches could occur due to the weakness of the IT system. This study seeks to discover the items and vulnerabilities that SMEs who have difficulties in information security due to technology limitations, human resources, and budget should first diagnose and check. First, to compare the existing domestic and foreign smart factory vulnerability classification systems and improve the current classification system, the latest smart factory vulnerability information is collected from NVD, CISA, and OWASP. Then, significant keywords are extracted from pre-processing, co-occurrence network analysis is performed, and the relationship between each keyword and vulnerability is discovered. Finally, the improvement points of the classification system are derived by mapping it to the existing classification system. Therefore, configuration and maintenance, communication and network, and software development were the items to be diagnosed and checked first, and vulnerabilities were denial of service (DoS), lack of integrity checking for communications, inadequate authentication, privileges, and access control in software in descending order of importance.

Effect of May 31, 2022 Miryang Forest Fire on Fine Particle Concentration in Nearby Urban Areas (2022년 5월 31일 발생한 밀양산불이 인근 도시 지역의 미세먼지 농도에 미치는 영향)

  • Byung-Il Jeon
    • Journal of Environmental Science International
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    • v.32 no.1
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    • pp.37-46
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    • 2023
  • This study investigated the effect of May 31, 2022 Miryang wildfire on fine particle concentrations in Busan and Gimhae, which are neighboring urban areas. In addition, fine particle characteristics and air pollution concentrations were investigated in Miryang, where haze occurred. The Miryang city wildfire that occurred on May 31, 2022, at 0925 LST, was driven by strong north winds and increased fine particle concentrations in Dongsangdong and Jangyoodong, Gimhae City, which are approximately 35 km to the southeast and south, respectively, of the wildfire occurrence site. Furthermore, the fine particle concentration in Myeongjidong, which is approximately 50 km south-southeast of the wildfire site, exhibited a temporary increase at 1400 LST owing to the effects of wildfire smoke. On the morning of June 1, the day after the fire, the Miryang area had very bad visibility because of the smoke from the fire. Therefore the PM10 and PM2.5 concentrations in Naeildong, 3 km south of the wildfire site, were 276 ㎍/㎥ and 222 ㎍/㎥, respectively, at 1200 LST. In addition, the gases O3, CO, and SO2 showed high concentrations at the time of haze generation. This study provides insights into policy making in response to the rapid increase in fine dust when wildfire occurs near cities.

Analysis of Research Trends in Homomorphic Encryption Using Bibliometric Analysis (서지통계학적 분석을 이용한 동형 암호의 연구경향 분석)

  • Akihiko Yamada;Eunsang Lee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.4
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    • pp.601-608
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    • 2023
  • Homomorphic encryption is a promising technology that has been extensively researched in recent years. It allows computations to be performed on encrypted data, without the need to decrypt it. In this paper, we perform bibliometric analysis to objectively and quantitatively analyze the research trends of homomorphic encryption technology using 6,047 homomorphic encryption papers from the Scopus database. Specifically, we analyze the number of papers by year, keyword co-occurrence, topic clustering, changes in related keywords over time, and country of homomorphic encryption research institutions. Our analysis results provide strategic directions for research and application of homomorphic encryption and can be a great help for subsequent research and industrial applications.

Combination of canagliflozin and puerarin alleviates the lipotoxicity to diabetic kidney in mice

  • Qian Zhu;Qu Zhou;Xiao-li Luo;Xu-jie Zhang;San-yu, Li
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.3
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    • pp.221-230
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    • 2023
  • Diabetic kidney disease is one of the most serious complications of diabetes. Although diabetic kidney disease can be effectively controlled through strict blood glucose management and corresponding symptomatic treatment, these therapies cannot reduce its incidence in diabetic patients. The sodium-glucose cotransporter 2 (SGLT2) inhibitors and the traditional Chinese herb "Gegen" have been widely used in diabetes-related therapy. However, it remains unclear whether the combined use of these two kinds of medicines contributes to an increased curative effect on diabetic kidney disease. In this study, we examined this issue by evaluating the efficacy of the combination of puerarin, an active ingredient of Gegen, and canagliflozin, an SGLT2 inhibitor for a 12-week intervention using a mouse model of diabetes. The results indicated that the combination of puerarin and canagliflozin was superior to canagliflozin alone in improving the metabolic and renal function parameters of diabetic mice. Our findings suggested that the renoprotective effect of combined puerarin and canagliflozin in diabetic mice was achieved by reducing renal lipid accumulation. This study provides a new strategy for the clinical prevention and treatment of diabetic kidney disease. The puerarin and SGLT2 inhibitor combination therapy at the initial stage of diabetes may effectively delay the occurrence of diabetic kidney injury, and significantly alleviate the burden of renal lipotoxicity.